Receiving time-overlapping downlink reference signals and channels

Abstract

Systems and methods are provided for determining a transmission configuration indication (TCI) state for an aperiodic (AP) channel state information reference signal (CSI-RS) that overlaps with a downlink transmission. In some embodiments, a method implemented by a wireless device includes receiving an AP CSI-RS in the same symbol as a downlink transmission scheduled by a DCI having two TCI states indicated in the DCI; receiving triggering for one or more AP CSI-RS at a scheduling offset between a last symbol of a PDCCH carrying the triggering DCI and a first symbol of an AP CSI-RS resource, where the scheduling offset is less than a wireless device reporting threshold; and determining that the downlink transmission is scheduled according to a scheme in which different sets of layers of the downlink transmission are received in different TCI states. In some embodiments, the wireless device applies a QCL assumption for the PDSCH transmission opportunity when receiving the AP CSI-RS.

Description

[Technical field]

[0001] Related Applications This application claims the benefit of Provisional Patent Application No. 63 / 008,386, filed April 10, 2020, the entire disclosure of which is incorporated herein by reference.

[0002] This disclosure relates to aperiodic CSI-RS reception when the aperiodic CSI-RS reception overlaps in time with a physical downlink shared channel (PDSCH). [Background technology]

[0003] NR Frame Structure and Resource Grid

[0004] NR uses Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) in both the downlink (DL) (i.e., from the network node, gNB, or base station to the user equipment or UE) and uplink (UL) (i.e., from the UE to the gNB). DFT-spread OFDM is also supported in the uplink. In the time domain, the NR downlink and uplink are organized into equal-sized subframes of 1 ms each. The subframes are further divided into multiple slots of equal duration. The slot length depends on the subcarrier spacing. For a subcarrier spacing of Δf=15 kHz, there is only one slot per subframe, and each slot consists of 14 OFDM symbols.

[0005] Data scheduling in NR is generally slot-based, and an example is shown in FIG. 1 with a 14-symbol slot, where the first two symbols contain the Physical Downlink Control Channel (PDCCH) and the rest contain the Physical Shared Data Channel, i.e., either the Physical Downlink Shared Channel (PDSCH) or the Physical Uplink Shared Channel (PUSCH).

[0006] Different subcarrier spacing values ​​are supported in NR. (Also called different numerologies) The supported subcarrier spacing values ​​are Δf = (15 × 2 μ ) kHz, where μ∈{0,1,2,3,4}. Δf=15 kHz is the basic subcarrier spacing. The slot durations in milliseconds for different subcarrier spacings are Given by TIFF0007648648000001.tif11170ms.

[0007] In the frequency domain, the system bandwidth is divided into resource blocks (RBs), each corresponding to 12 adjacent subcarriers. The RBs are numbered starting with 0 from one end of the system bandwidth. The basic NR physical time-frequency resource grid is shown in Figure 2, where only one resource block (RB) in a 14-symbol slot is shown. One OFDM subcarrier in one OFDM symbol interval forms one resource element (RE).

[0008] Downlink transmissions may be dynamically scheduled, i.e., in each slot, the gNB transmits downlink control information (DCI) on the PDCCH regarding which UEs data should be transmitted to and on which RBs and OFDM symbols in the current or future downlink slots the data will be transmitted. The PDCCH is generally transmitted in the first few OFDM symbols in each slot in NR. UE data is carried on the PDSCH.

[0009] There are three DCI formats defined for scheduling PDSCH in NR: DCI format 1_0, DCI format 1_1, and DCI format 1_2. DCI format 1_0 has a smaller size than DCI 1_1 and can be used when the UE is not yet attached to the network, and DCI format 1_1 can be used to schedule MIMO (multiple-input multiple-output) transmissions with up to two transport blocks (TB). DCI format 1_2 is introduced in NR Release 16 (Rel-16) to support configurable sizes for some bit fields in the DCI.

[0010] One or more of the following bit fields may be included in the DCI: Frequency Domain Resource Allocation (FDRA), Time Domain Resource Allocation (TDRA), Modulation and Coding Scheme (MCS), New Data Indicator (NDI), Redundancy Version (RV), HARQ Process Number, PUCCH Resource Indicator (PRI), PDSCH-to-HARQ_feedback Timing Indicator (K1), Antenna Port(s), and Transmission Configuration Indication (TCI).

[0011] If the UE first detects and decodes the PDCCH, and the decoding is successful, the UE then decodes the corresponding PDSCH based on the decoded DCI carried in the PDCCH. The PDSCH decoding status is sent back to the gNB in ​​the form of a HARQ acknowledgement or HARQ-ACK in the PUCCH resource indicated by the PRI. An example is shown in Figure 3. The time offset T1 between the reception of the DL DCI and the corresponding PDSCH is determined by the slot offset and the starting symbol of the PDSCH, which are indicated in the TDRA in the DCI. The time offset T2 between the reception of the DL DCI and the corresponding HARQ ACK is provided by the PDSCH-to-HARQ_feedback timing indicator in the DCI.

[0012] Time Domain Resource Allocation

[0013] When a UE is scheduled to receive a PDSCH by a DCI, the time domain resource allocation (TDRA) field value m of the DCI provides the row index m+1 to the time domain resource allocation table. When a DCI is detected in the UE-specific search space, the PDSCH time domain resource allocation follows the RRC configured TDRA list according to the RRC parameter pdsch-TimeDomainAllocationList provided in the UE-specific PDSCH configuration pdsch-Config. Each TDRA entry in the TDRA list specifies the slot offset K0 between the PDSCH and the PDCCH that schedules the PDSCH, the start and length indicator SLIV, the PDSCH mapping type (either Type A or Type B) to be assumed in the PDSCH reception, and optionally a repetition number RepNumR16.

[0014] TCI Status

[0015] A demodulation reference signal (DM-RS) is used for coherent demodulation of the PDSCH. The DM-RS is confined to the resource block carrying the associated PDSCH and is mapped onto the assigned resource elements (REs) of the OFDM time-frequency grid in NR so that the receiver can efficiently handle time / frequency selective fading wireless channels. A PDSCH may have one or multiple DMRSs, each associated with an antenna port. The antenna port used for the PDSCH is indicated in the DCI that schedules the PDSCH.

[0016] Several signals may be transmitted from different co-located antenna ports. These signals may have the same large-scale characteristics, for example, in terms of Doppler shift / spread, average delay spread, average delay, or direction of arrival, as measured at the receiver. These antenna ports are then said to be Quasi Co-Located (QCL). The network may then signal to the UE that two antenna ports are QCLed. If the UE knows that two antenna ports are QCLed with respect to a certain parameter (e.g., Doppler spread), the UE may estimate that parameter based on a reference signal transmitted on one of those antenna ports and use that estimate when receiving another reference signal or physical channel on the other antenna port. In general, the first antenna port is represented by a measurement reference signal (known as source RS), such as a channel state information reference signal (CSI-RS), and the second antenna port is a DMRS (known as target RS) for PDSCH reception.

[0017] In NR, the QCL relationship between the demodulation reference signal (DMRS) in the PDSCH and other reference signals is described by the transmission configuration indicator (TCI) state. The UE can be configured through radio resource control (RRC) signaling with up to 128 TCI states in NR frequency range 2 (FR2) and up to 8 TCI states in NR frequency range (FR1) depending on the UE capabilities. Each TCI state contains QCL information for the purpose of PDSCH reception. The UE can be dynamically signaled one or two TCI states in the TCI field in the DCI that schedules the PDSCH.

[0018] The QCL relationship between the DMRS in the PDCCH and other reference signals is described by the TCI state of the control resource set (CORESET) on which the PDCCH is transmitted. For each CORESET configured in the UE, a list of TCI states is RRC configured, one of which is activated by the MAC CE. In NR Rel-15, up to three CORESETs per Bandwidth Part (BWP) can be configured for the UE. In NR Rel-16, up to five CORESETs per BWP can be configured for the UE, depending on the capabilities.

[0019] Currently, several challenges exist. Existing NR standards specify UE behavior when aperiodic CSI-RS collides with PDSCH when PDSCH is indicated in a single TCI state. However, UE behavior in other situations when aperiodic CSI-RS collides with PDSCH is not specified. Therefore, improvements are needed to handle collisions. Summary of the Invention

[0020] Systems and methods are provided for determining a transmission configuration indication (TCI) state for an aperiodic (AP) channel state information reference signal (CSI-RS) that overlaps with a physical downlink shared channel (PDSCH) transmission. In some embodiments, a method implemented by a wireless device for determining a TCI state for receiving one or more AP CSI-RS includes one or more of: receiving one or more AP CSI-RS in the same symbol(s) as a downlink transmission(s) scheduled by a DCI with two TCI states indicated in the DCI, receiving triggering of the one or more AP CSI-RS at a scheduling offset between a last symbol of a PDCCH carrying the triggering DCI and a first symbol of an AP CSI-RS resource, where the scheduling offset is less than a wireless device reported threshold, and determining that the downlink transmission is scheduled according to one of the group consisting of “TDMSchemeA”, “FDMSchemeA”, “FDMSchemeB”, and a scheme in which different sets of layers of a downlink transmission are received in different TCI states. In some embodiments, depending on the circumstances, the wireless device applies a QCL assumption for the PDSCH transmission opportunity when receiving the AP CSI-RS.

[0021] In some embodiments, a method implemented by a base station for indicating a TCI state for receiving one or more AP CSI-RS includes one or more of: transmitting to a wireless device one or more AP CSI-RS in the same symbol(s) as a downlink transmission(s) scheduled by a DCI with two TCI states indicated in the DCI; triggering the one or more AP CSI-RS at a scheduling offset between a last symbol of a PDCCH carrying a triggering DCI and a first symbol of an AP CSI-RS resource, where the scheduling offset is less than a wireless device reporting threshold; and scheduling the downlink transmission according to one of the group consisting of "TDMSchemeA", "FDMSchemeA", "FDMSchemeB", and a scheme in which different sets of layers of a downlink transmission are received in different TCI states. In some embodiments, optionally, the base station assumes that the wireless device applies a QCL assumption for a PDSCH transmission opportunity when receiving the AP CSI-RS.

[0022] Some embodiments may provide one or more of the following technical advantages(s): The proposed solution specifies the UE behavior (i.e., what QCL assumptions the UE makes) for receiving aperiodic CSI-RS when it collides with PDSCH when PDSCH is indicated in two TCI states. One benefit is that the proposed solution specifies with which QCL characteristics the colliding aperiodic CSI-RS should be received, which was not specified in NR before. With the proposed solution, aperiodic CSI-RS can be flexibly triggered in overlapping symbols with PDSCH scheduled according to one of the single PDCCH-based NC-JT schemes "FDMSchemeA", "FDMSchemeB", and "TDMSchemeA".

[0023] In some embodiments, the downlink transmission(s) comprise(s) a PDSCH transmission(s).In some embodiments, the wireless device reporting threshold comprises a beamSwitchTiming value.

[0024] In some embodiments, the PDSCH is scheduled according to one of the group consisting of "FDMSchemeA", "FDMSchemeB", and a scheme in which different sets of layers of the PDSCH are received in different TCI states. In some embodiments, the scheduling offset from the last symbol of the PDCCH to the first symbol of the PDSCH is greater than or equal to a threshold timeDurationForQCL.

[0025] In some embodiments, when a single triggered AP CSI-RS is in the same symbol as the PDSCH, the method also includes applying a QCL assumption given by a first indicated TCI state in the DCI for the PDSCH when the wireless device receives the AP CSI-RS. In some embodiments, when two triggered AP CSI-RS are in the same symbol as the PDSCH, the method also includes applying a QCL assumption given by a first indicated TCI state and a second indicated TCI state in the DCI for the PDSCH when the wireless device receives the first AP CSI-RS and the second AP CSI-RS, respectively.

[0026] In some embodiments, the first triggered AP CSI-RS and the second triggered AP CSI-RS follow a classification of corresponding CSI-RS resource identifiers or a classification of corresponding CSI-RS resource set identifiers to which the two AP CSI-RS belong. In some embodiments, the scheduling offset from the last symbol of the PDCCH to the first symbol of the PDSCH is less than a threshold timeDurationForQCL.

[0027] In some embodiments, when a single triggered AP CSI-RS is in the same symbol as the PDSCH, the method also includes applying a QCL assumption given by a first default TCI state for the PDSCH when the wireless device receives the AP CSI-RS. In some embodiments, when two triggered AP CSI-RS are in the same symbol as the PDSCH, the method also includes applying a QCL assumption given by a first default TCI state and a second default TCI state for the PDSCH when the wireless device receives the first AP CSI-RS and the second AP CSI-RS, respectively.

[0028] In some embodiments, the first triggered AP CSI-RS and the second triggered AP CSI-RS follow a classification of corresponding CSI-RS resource identifiers or a classification of corresponding CSI-RS resource set identifiers to which the two AP CSI-RS belong.

[0029] In some embodiments, the PDSCH is scheduled according to "TDMSchemeA". In some embodiments, a scheduling offset from the last symbol of the PDCCH to the first symbol of the first PDSCH transmission opportunity is greater than or equal to a threshold timeDurationForQCL. In some embodiments, when the single triggered AP CSI-RS is in the same symbol as the first PDSCH transmission opportunity, the method also includes applying a QCL assumption given by a first indicated TCI state in the DCI for the first PDSCH transmission opportunity when the wireless device receives the AP CSI-RS. In some embodiments, when the single triggered AP CSI-RS is in the same symbol as the second PDSCH transmission opportunity, the method also includes applying a QCL assumption given by a second indicated TCI state in the DCI for the second PDSCH transmission opportunity when the wireless device receives the AP CSI-RS.

[0030] In some embodiments, the scheduling offset from the last symbol of the PDCCH to the first symbol of the first PDSCH transmission opportunity and the scheduling offset from the last symbol of the PDCCH to the first symbol of the second PDSCH transmission opportunity are both less than a threshold timeDurationForQCL. In some embodiments, when the single triggered AP CSI-RS is in the same symbol as the first PDSCH transmission opportunity, the method also includes applying a QCL assumption provided by a first default TCI state in the DCI for the first PDSCH transmission opportunity when the wireless device receives the AP CSI-RS. In some embodiments, when the single triggered AP CSI-RS is in the same symbol as the second PDSCH transmission opportunity, the method also includes applying a QCL assumption provided by a second indicated TCI state in the DCI for the second PDSCH transmission opportunity when the wireless device receives the AP CSI-RS.

[0031] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several aspects of the present disclosure and, together with the description, serve to explain the principles of the disclosure. [Brief description of the drawings]

[0032] [Figure 1] FIG. 1 illustrates an example of data scheduling in NR, which is generally slot-based, with a 14-symbol slot in which the first two symbols contain the Physical Downlink Control Channel (PDCCH) and the rest contain the Physical Shared Data Channel, i.e., either the Physical Downlink Shared Channel (PDSCH) or the Physical Uplink Shared Channel (PUSCH). [Diagram 2] FIG. 1 illustrates a basic NR physical time-frequency resource grid. [Diagram 3] FIG. 1 illustrates an example in which PDSCH decoding status is sent back to the gNB in ​​the form of a HARQ acknowledgement in a PUCCH resource indicated by the PRI, according to some embodiments of the present disclosure. [Figure 4] FIG. 1 illustrates an example of a cellular communication system in which embodiments of the present disclosure may be implemented. [Diagram 5] FIG. 1 illustrates a case where data is sent to a UE on two TRPs, with each TRP carrying one TB mapped to one codeword, in accordance with some embodiments of the present disclosure. [Figure 6] FIG. 1 illustrates an example relationship between TCI states and DM-RS CDM groups for a multiple PDCCH multi-TRP scenario, according to some embodiments of the present disclosure. [Figure 7] FIG. 1 illustrates an example of PDSCH transmission on two TRPs using a single DCI, in accordance with some embodiments of the present disclosure. [Figure 8] FIG. 1 illustrates an example of a multi-TRP PDSCH transmission using FDMSchemeA in accordance with some embodiments of the present disclosure. [Figure 9] FIG. 1 illustrates an example data transmission using FDMSchemeB in which PDSCH#1 is transmitted in PRG{0,2,4} from TRP1 and PDSCH#2 with the same TB is transmitted in PRG{1,3,5} from TRP2, according to some embodiments of the present disclosure. [Figure 10] FIG. 1 illustrates an example data transmission using TDMSchemeA where PDSCH repetition occurs in a minislot of four OFDM symbols within a slot, in accordance with some embodiments of the present disclosure. [Figure 11] FIG. 1 illustrates an example multi-TRP data transmission using a slot-based TDM scheme in accordance with some embodiments of the present disclosure. [Figure 12] FIG. 2 illustrates an example of CSI-RS REs for 12 antenna ports, with one RE per RB per port shown, in accordance with some embodiments of the present disclosure. [Figure 13] 1 illustrates a method implemented by a wireless device for determining a TCI state for receiving one or more AP CSI-RS, according to some embodiments of the present disclosure. [Figure 14]1 illustrates a method implemented by a base station for indicating a TCI state for receiving one or more AP CSI-RS, according to some embodiments of the present disclosure. [Figure 15] FIG. 2 illustrates an example of embodiment 1 considering AP CSI-RS collision with PDSCH scheduled according to “TDMSchemeA” in accordance with some embodiments of the present disclosure. [Figure 16] FIG. 13 illustrates a second example of embodiment 1 considering AP CSI-RS collision with PDSCH scheduled according to “TDMSchemeA” in accordance with some embodiments of the present disclosure. [Figure 17] FIG. 11 is a diagram illustrating a first example of embodiment 2 considering AP CSI-RS collision with PDSCH scheduled according to "TDMSchemeA." [Figure 18] FIG. 13 illustrates a second example of embodiment 2 considering AP CSI-RS collision with PDSCH scheduled according to “TDMSchemeA” in accordance with some embodiments of the present disclosure. [Figure 19] FIG. 13 illustrates a first example of embodiment 3 considering AP CSI-RS collision with PDSCH scheduled according to “TDMSchemeA” in accordance with some embodiments of the present disclosure. [Figure 20] FIG. 13 illustrates a second example of embodiment 3 considering AP CSI-RS collision with PDSCH scheduled according to “TDMSchemeA” in accordance with some embodiments of the present disclosure. [Figure 21] FIG. 13 illustrates a first example of embodiment 4 considering AP CSI-RS collision with a PDSCH scheduled according to a single PDCCH-based NC-JT scheme, in which a first TCI state is assumed for an AP CSI-RS, according to some embodiments of the present disclosure. [Figure 22]FIG. 13 illustrates a second example of embodiment 4 considering AP CSI-RS collision with a PDSCH scheduled according to a single PDCCH-based NC-JT scheme, in which a first TCI state and a second TCI state are assumed for a first AP CSI-RS and a second AP CSI-RS, respectively, in accordance with some embodiments of the present disclosure. [Figure 23] FIG. 11 illustrates a first example of a fifth embodiment in which a first default TCI state is assumed for an AP CSI-RS, taking into account AP CSI-RS collisions with a PDSCH scheduled according to a single PDCCH-based NC-JT scheme, in accordance with some embodiments of the present disclosure. [Figure 24] FIG. 13 illustrates a second example of embodiment 5 considering AP CSI-RS collision with a PDSCH scheduled according to a single PDCCH-based NC-JT scheme, in which a first default TCI state and a second default TCI state are assumed for a first AP CSI-RS and a second AP CSI-RS, respectively, in accordance with some embodiments of the present disclosure. [Diagram 25] 1 is a schematic block diagram of a radio access node according to some embodiments of the present disclosure. [Figure 26] FIG. 2 is a schematic block diagram illustrating a virtualized embodiment of a radio access node, in accordance with certain embodiments of the present disclosure. [Figure 27] 4 is a schematic block diagram of a radio access node according to some other embodiments of the present disclosure. [Figure 28] 1 is a schematic block diagram of a wireless communication device according to some embodiments of the present disclosure. [Figure 29] 1 is a schematic block diagram of a wireless communication device according to some other embodiments of the present disclosure. [Diagram 30] FIG. 1 is a diagram of a communications system including a communications network, such as a 3GPP-type cellular network, comprising an access network, such as a RAN, and a core network, according to one embodiment and some other embodiments of the present disclosure. [Diagram 31]A diagram showing an example implementation of a UE, a base station, and a host computer according to one embodiment and some other embodiments of the present disclosure. [Diagram 32] 1 is a flow chart illustrating a method implemented in a communication system according to one embodiment. [Diagram 33] 1 is a flow chart illustrating a method implemented in a communication system according to one embodiment. [Diagram 34] 1 is a flow chart illustrating a method implemented in a communication system according to one embodiment. [Diagram 35] 1 is a flow chart illustrating a method implemented in a communication system according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] The embodiments described below represent information to enable those skilled in the art to practice the embodiments and illustrate the best modes of practicing the embodiments. Upon reading the following description in light of the accompanying drawings, those skilled in the art will understand the concepts of the present disclosure and recognize applications of these concepts not specifically addressed herein. It is to be understood that these concepts and applications fall within the scope of the present disclosure.

[0034] Wireless Node: As used herein, a "wireless node" is either a wireless access node or a wireless communication device.

[0035] Radio Access Node: As used herein, a "radio access node" or "radio network node" or "radio access network node" is any node in a radio access network (RAN) of a cellular communication network that operates to transmit and / or receive signals wirelessly. Some examples of radio access nodes include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a 3rd Generation Partnership Project (3GPP) 5th Generation (5G) NR network, or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high power or macro base station, a low power base station (e.g., a micro base station, a pico base station, a home eNB, etc.), a relay node, a network node implementing part of the functionality of a base station (e.g., a network node implementing a gNB central unit (gNB-CU) or a network node implementing a gNB distributed unit (gNB-DU)) or a network node implementing part of the functionality of some other type of radio access node.

[0036] Core Network Node: As used herein, a "core network node" is any type of node in a core network or any node that implements a core network function. Some examples of core network nodes include, for example, a Mobility Management Entity (MME), a Packet Data Network Gateway (P-GW), a Service Capability Publication Function (SCEF), a Home Subscriber Server (HSS), etc. Some other examples of core network nodes include nodes that implement an Access and Mobility Management Function (AMF), a User Plane Function (UPF), a Session Management Function (SMF), an Authentication Server Function (AUSF), a Network Slice Selection Function (NSSF), a Network Publication Function (NEF), a Network Function (NF) Repository Function (NRF), a Policy Control Function (PCF), a Unified Data Management (UDM), etc.

[0037] Communication Device: As used herein, a "communication device" is any type of device that has access to an access network. Some examples of communication devices include, but are not limited to, a mobile phone, a smartphone, a sensor device, a meter, a vehicle, a household appliance, a medical appliance, a media player, a camera, or any type of consumer electronic device, such as, but not limited to, a television, a radio, a lighting device, a tablet computer, a laptop computer, or a personal computer (PC). A communication device may be a portable, handheld, computer-equipped, or vehicle-mounted mobile device enabled to communicate voice and / or data via wireless or wired connections.

[0038] Wireless Communication Device: One type of communication device is a wireless communication device, which may be any type of wireless device having access to (i.e., served by) a wireless network (e.g., a cellular network). Some examples of wireless communication devices include, but are not limited to, user equipment devices (UEs) in 3GPP networks, machine-type communication (MTC) devices, and Internet of Things (IoT) devices. Such wireless communication devices may be or may be integrated into mobile phones, smartphones, sensor devices, meters, vehicles, household appliances, medical appliances, media players, cameras, or any type of consumer electronics, such as, but not limited to, televisions, radios, lighting devices, tablet computers, laptop computers, or PCs. Wireless communication devices may be portable, handheld, computer-equipped, or vehicle-mounted mobile devices enabled to communicate voice and / or data over a wireless connection.

[0039] Network Node: As used herein, a "network node" is any node that is part of either the RAN or the core network of a cellular communications network / system.

[0040] It should be noted that the description provided herein focuses on 3GPP cellular communication systems, and therefore 3GPP terminology or terminology similar to 3GPP terminology is often used, however, the concepts disclosed herein are not limited to 3GPP systems.

[0041] It should be noted that in the description herein, reference may be made to the term "cell." However, it is important to note that, particularly with respect to 5G NR concepts, a beam may be used in place of a cell, and thus the concepts described herein are equally applicable to both cells and beams.

[0042] FIG. 4 illustrates an example of a cellular communication system 400 in which embodiments of the present disclosure may be implemented. In the embodiments described herein, the cellular communication system 400 is a 5G system (5GS) including an NR RAN or an LTE RAN (i.e., an Enhanced Universal Terrestrial Radio Access (E-UTRA) RAN). In this example, the RAN includes base stations 402-1 and 402-2, referred to as gNBs in 5G NR (e.g., LTE RAN nodes connected to a 5G Core (5GC), referred to as gn-eNBs), which control corresponding (macro) cells 404-1 and 404-2. The base stations 402-1 and 402-2 are generally referred to herein collectively as base stations 402 and individually as base stations 402. Similarly, the (macro) cells 404-1 and 404-2 are generally referred to herein collectively as (macro) cells 404 and individually as (macro) cells 404. The RAN may also include several low power nodes 406-1-406-4 that control corresponding small cells 408-1-408-4. The low power nodes 406-1-406-4 may be small base stations (such as pico or femto base stations), or remote radio heads (RRHs), or the like. Although not specifically shown, one or more of the small cells 408-1-408-4 may alternatively be provided by the base station 402. The low power nodes 406-1-406-4 are generally referred to herein collectively as low power nodes 406 and individually as low power nodes 406. Similarly, the small cells 408-1-408-4 are generally referred to herein collectively as small cells 408 and individually as small cells 408. The cellular communication system 400 also includes a core network 410, referred to in 5GS as 5G Core (5GC). The base station 402 (and optionally the low power node 406 ) is connected to a core network 410 .

[0043] The base station 402 and the low power node 406 serve wireless communication devices 412-1 through 412-5 in corresponding cells 404 and 408. The wireless communication devices 412-1 through 412-5 are generally referred to herein collectively as wireless communication devices 412 and individually as wireless communication devices 412. In the following description, the wireless communication devices 412 are often UEs, although the disclosure is not limited thereto.

[0044] Downlink transmissions may be dynamically scheduled, i.e., in each slot, the gNB transmits downlink control information (DCI) on the PDCCH regarding which UE data should be transmitted to and on which RBs and OFDM symbols in the current downlink slot the data is transmitted. The PDCCH is generally transmitted in the first few OFDM symbols in each slot in NR. UE data is carried on the PDSCH.

[0045] There are three DCI formats defined for scheduling PDSCH in NR: DCI format 1_0, DCI format 1_1, and DCI format 1_2. DCI format 1_0 has a smaller size than DCI 1_1 and can be used when the UE is not connected to the network, and DCI format 1_1 can be used to schedule MIMO (multiple-input multiple-output) transmissions with up to two transport blocks (TB). DCI format 1_2 is introduced in NR Release 16 (Rel-16) to support configurable sizes for some bit fields in the DCI.

[0046] One or more of the following bit fields may be included in the DCI: Frequency Domain Resource Allocation (FDRA), Time Domain Resource Allocation (TDRA), Modulation and Coding Scheme (MCS), New Data Indicator (NDI), Redundancy Version (RV), HARQ Process Number, PUCCH Resource Indicator (PRI), PDSCH-to-HARQ_feedback Timing Indicator (K1), Antenna Port(s), and Transmission Configuration Indication (TCI).

[0047] If the UE first detects and decodes the PDCCH, and the decoding is successful, the UE then decodes the corresponding PDSCH based on the decoded DCI carried in the PDCCH. The PDSCH decoding status is sent back to the gNB in ​​the form of a HARQ acknowledgement in the PUCCH resource indicated by the PRI. An example is shown in Figure 3. The time offset T1 between the reception of the DL DCI and the corresponding PDSCH is determined by the slot offset and the starting symbol of the PDSCH, which are indicated in the TDRA in the DCI. The time offset T2 between the reception of the DL DCI and the corresponding HARQ ACK is provided by the PDSCH-to-HARQ_feedback timing indicator in the DCI.

[0048] Time Domain Resource Allocation

[0049] When a UE is scheduled to receive a PDSCH by a DCI, the time domain resource allocation (TDRA) field value m of the DCI provides the row index m+1 to the time domain resource allocation table. When a DCI is detected, the PDSCH time domain resource allocation follows the RRC configured TDRA list according to the RRC parameter pdsch-TimeDomainAllocationList provided in the UE specific PDSCH configuration pdsch-Config. Each TDRA entry in the TDRA list specifies the slot offset K0 between the PDSCH and the PDCCH that schedules the PDSCH, the start and length indicator SLIV, the PDSCH mapping type (either Type A or Type B) to be assumed in the PDSCH reception, and optionally a repetition number RepNumR16.

[0050] TCI Status

[0051] A demodulation reference signal (DM-RS) is used for coherent demodulation of the PDSCH. The DM-RS is confined to the resource block carrying the associated PDSCH and is mapped onto the assigned resource elements (REs) of the OFDM time-frequency grid in NR so that the receiver can efficiently handle time / frequency selective fading wireless channels. A PDSCH may have one or multiple DMRSs, each associated with an antenna port. The antenna port used for the PDSCH is indicated in the DCI that schedules the PDSCH.

[0052] Several signals may be transmitted from different antenna ports at the same location. These signals may have the same large-scale characteristics, for example, in terms of Doppler shift / spread, average delay spread, or average delay, as measured at the receiver. These antenna ports are then said to be quasi-colocated (QCL). The network may then signal to the UE that two antenna ports are QCLed. If the UE knows that two antenna ports are QCLed with respect to a certain parameter (e.g., Doppler spread), the UE may estimate that parameter based on a reference signal transmitted on one of those antenna ports and use that estimate when receiving another reference signal or physical channel on the other antenna port. In general, the first antenna port is represented by a measurement reference signal, such as a channel state information reference signal (CSI-RS) (known as source RS), and the second antenna port is a DMRS (known as target RS) for PDSCH reception.

[0053] In NR, the QCL relationship between the demodulation reference signal (DMRS) in the PDSCH and other reference signals is described by the TCI state. The UE can be configured through RRC signaling with up to 128 TCI states in Frequency Range 2 (FR2) and up to 8 TCI states in FR1 depending on the UE capabilities. Each TCI state contains QCL information for the purpose of PDSCH reception. The UE can be dynamically signaled one or two TCI states in the TCI field in the DCI that schedules the PDSCH.

[0054] The QCL relationship between the DMRS in the PDCCH and other reference signals is described by the TCI state of the control resource set (CORESET) on which the PDCCH is transmitted. For each CORESET configured in the UE, a list of TCI states is RRC configured, one of which is activated by the MAC CE. In NR Rel-15, up to three CORESETs per Bandwidth Part (BWP) can be configured for the UE. In NR Rel-16, up to five CORESETs per BWP can be configured for the UE, depending on the capabilities.

[0055] PDSCH transmission on multiple transmission points or panels (TRP)

[0056] In one scenario, downlink data is transmitted on multiple TRPs with different MIMO layers transmitted on different TRPs. This is called non-coherent joint transmission (NC-JT). In another scenario, different time / frequency resources may be assigned to different TRPs and one or more PDSCHs are transmitted on different TRPs. Two ways of scheduling multi-TRP transmissions are specified in NR Rel-16: multi-PDCCH-based multi-TRP transmission and single-PDCCH-based multi-TRP transmission. Multi-PDCCH-based multi-TRP transmission and single-PDCCH-based multi-TRP transmission can be used to serve downlink eMBB traffic as well as downlink URLLC traffic to a UE.

[0057] Multi-PDCCH based DL data transmission over multiple transmission points (TRPs)

[0058] An example is shown in Figure 5 where data is sent to the UE on two TRPs, each carrying one TB mapped to one codeword. When the UE has four receive antennas but each of the TRPs has only two transmit antennas, the UE can support up to four MIMO layers, but each TRP can transmit at most two MIMO layers. In this case, by sending data to the UE on two TRPs, the peak data rate to the UE can be increased since up to four aggregated layers from the two TRPs can be used. This is beneficial when the traffic load, and therefore the resource utilization, is low in each TRP. In this example, a single scheduler is used to schedule data on the two TRPs. One PDCCH is transmitted from each of the two TRPs in a slot, each of which schedules one PDSCH. This is called a multi-PDCCH or multi-DCI scheme, where the UE receives two PDCCHs and associated two PDSCHs in a slot from two TRPs.

[0059] The NR specification 3GPP TS38.211 has the following restrictions:

[0060] "The UE may assume that the PDSCH DM-RS in the same CDM group are quasi-co-located with respect to Doppler shift, Doppler spread, mean delay, delay spread, and spatial Rx."

[0061] If a UE is not scheduled on all DMRS ports in a CDM group, there may be another UE scheduled simultaneously using the remaining ports of that CDM group. The UE can then estimate the channel (and therefore the interfering signal) for that other UE to perform coherent interference suppression. This is therefore useful in MU-MIMO scheduling and UE interference suppression.

[0062] For a multi-TRP scenario in which a UE receives a PDSCH via multiple PDCCHs transmitted from different TRPs, the signals transmitted from different TRPs are most likely not quasi-collocated since the TRPs may be spatially separated. In this case, the PDSCHs transmitted from different TRPs have different TCI states associated with them. Furthermore, according to the above restrictions from 3GPP TS38.211, two PDSCH DM-RSs associated with two TRPs must belong to different DM-RS CDM groups (since the two PDSCH DM-RSs are not QCL, they cannot belong to the same DM-RS CDM group). Figure 6 illustrates an exemplary relationship between TCI states and DM-RS CDM groups for a multi-PDCCH multi-TRP scenario. In this example, PDSCH1 is associated with TCI state p, and PDSCH2 is associated with TCI state q. The PDSCH DM-RSs from different TRPs also belong to different DM-RS CDM groups since they are not quasi-collocated. In this example, the DMRS for PDSCH1 belongs to CDM group u, and the DMRS for PDSCH2 belongs to CDM group v.

[0063] Single PDCCH-based DL data transmission over multiple transmission points (TRPs)

[0064] A PDSCH may be transmitted to a UE from multiple TRPs. Different TRPs may be in different physical locations and / or have different beams, and therefore the propagation channels may be different. To facilitate receiving PDSCH data from different TRPs or beams, a UE may be indicated with two TCI states, each associated with a TRP or beam, by a single code point in a TCI field in the DCI.

[0065] An example of PDSCH transmission on two TRPs using a single DCI, where different layers of a PDSCH with a single codeword (e.g., CW0) are sent on the two TRPs, each associated with a different TCI state, is shown in Figure 7. In this case, two DMRS ports, one for each layer in the two CDM groups, are also signaled to the UE. A first TCI state is associated with the DMRS port in the first CDM group, and a second TCI state is associated with the DMRS port in the second CDM group. This approach is often referred to as NC-JT (non-coherent joint transmission) or scheme 1a in NR Rel-16 3GPP discussions.

[0066] Transmitting the PDSCH over multiple TRPs can also be used to improve PDSCH transmission reliability for URLLC applications. Several schemes are introduced in NR Rel-16, including "FDMSchemeA", "FDMSchemeB", "TDMSchemeA", and slot-based TDM schemes. Note that the terminology Scheme 4 is used in discussions involving the slot-based TDM scheme in NR Rel-16 3GPP discussions.

[0067] An example of a multi-TRP PDSCH transmission using FDMSchemeA is shown in Figure 8, where the PDSCH is sent on TRP1 in PRG (precoding RB group) {0,2,4} and on TRP2 in PRG {1,3,5}. The transmission from TRP1 is associated with TCI state 1, and the transmission from TRP2 is associated with TCI state 2. For FDMSchemeA, the DMRS port can be the same (i.e., DMRS port 0 is used for both transmissions) since the transmissions from TRP1 and TRP2 do not overlap. The PDSCH is scheduled by the PDCCH sent on TRP1.

[0068] 9 shows an example data transmission using FDMSchemeB where PDSCH#1 is transmitted in PRG{0,2,4} from TRP1 and PDSCH#2 with the same TB is transmitted in PRG{1,3,5} from TRP2. The transmission from TRP1 is associated with TCI state 1 and the transmission from TRP2 is associated with TCI state 2. For FDMSchemeB, the DMRS port can be the same (i.e., DMRS port 0 is used for both transmissions) since the transmissions from TRP1 and TRP2 do not overlap. The two PDSCHs carry the same coded data payload but with the same or different redundancy versions (RVs) so that the UE can perform soft combining of the two PDSCHs to achieve more reliable reception.

[0069] 10 shows an example data transmission using TDM Scheme A where PDSCH repetition occurs in a minislot of 4 OFDM symbols within a slot. Each PDSCH may be associated with the same or different RV. The transmission of PDSCH#1 from TRP1 is associated with the first TCI state and the transmission of PDSCH#2 from TRP2 is associated with the second TCI state.

[0070] An exemplary multi-TRP data transmission using a slot-based TDM scheme, in which four PDSCHs for the same TB are transmitted on two TRPs and in four consecutive slots, is shown in Figure 11. Each PDSCH is associated with a different RV. The transmission of odd-numbered PDSCHs from TRP1 is associated with a first TCI state, and the transmission of even-numbered PDSCHs from TRP2 is associated with a second TCI state.

[0071] For all single PDCCH based DL multi-TRP PDSCH schemes, a single DCI transmitted from one TRP is used to schedule multiple PDSCH transmissions on two TRPs. The network configures the UE in multiple TCI states via RRC, and a new MAC CE was introduced in NR Rel-16. This MAC CE can be used to map codepoints in the TCI field to one or two TCI states.

[0072] Default TCI state(s)

[0073] Single TRP transmission

[0074] If a TCI codepoint is not mapped to two different TCI states and the time offset between reception of a DL DCI and the corresponding PDSCH is smaller than a threshold timeDurationForQCL configured by higher layers, instead of using the TCI state indicated in the TCI field in the DCI scheduling the PDSCH, the UE may assume that the TCI state for the PDSCH is given by the TCI state activated for the CORESET with the lowest ControlResourceSetId among one or more CORESETs in the latest slot in the active BWP of the serving cell monitored by the UE. That TCI state is referred to herein as the default TCI state. If none of the configured TCI states for the serving cell of a scheduled PDSCH contains "QCL-TypeD", the UE shall derive the other QCL assumption from the TCI state indicated by the DCI for that scheduled PDSCH, regardless of the time offset between reception of a DL DCI and the corresponding PDSCH.

[0075] Multi-TRP transmission

[0076] If the offset between reception of a DL DCI and the corresponding PDSCH is less than a threshold timeDurationForQCL, and at least one configured TCI state for the serving cell of the scheduled PDSCH includes "QCL-TypeD", and at least one TCI codepoint is configured with two TCI states, the UE may assume that the TCI state for the PDSCH is given by the TCI state corresponding to the lowest codepoint among the TCI codepoints that include two different TCI states. In this case, the two TCI states are default TCI states.

[0077] The default TCI state corresponds to the Rx beam used by the UE to receive (and buffer) the PDSCH before the corresponding DCI is decoded (because before DCI decoding, the UE does not know what TCI state(s) are required to receive the PDSCH). In some cases, the wrong Rx beam may be used and the PDSCH may be lost if the time offset between the DCI and the PDSCH is below a threshold, which is not known before the DCI is decoded.

[0078] Channel State Information Reference Signal (CSI-RS)

[0079] In the CSI measurement and feedback, the CSI-RS is defined. The CSI-RS is transmitted on each transmit antenna (or antenna port) and is used by the UE to measure the downlink channel between each of the transmit antenna ports and each receive antenna. The antenna port is also called a CSI-RS port. The supported number of antenna ports in NR is {1, 2, 4, 8, 12, 16, 24, 32}. By measuring the received CSI-RS, the UE can estimate the channel that the CSI-RS is traversing, including the radio propagation channel and the antenna gain. The CSI-RS for the above purpose is also called a non-zero power (NZP) CSI-RS.

[0080] The NZP CSI-RS may be configured to be transmitted in some REs in a slot and in some slots. Figure 12 shows an example of CSI-RS REs for 12 antenna ports, where one RE per RB per port is shown.

[0081] In addition, a CSI interference measurement resource (CSI-IM) for the UE to measure interference is also defined in NR. The CSI-IM resource contains either 4 REs, i.e., 4 adjacent REs in frequency in the same OFDM symbol, or 2×2 adjacent REs in both time and frequency in a slot. By measuring both the channel based on the NZP CSI-RS and the interference based on the CSI-IM, the UE can estimate the effective channel and noise plus interference to determine the CSI, i.e., rank, precoding matrix, and channel quality.

[0082] In NR, CSI-RS can be aperiodic, semi-persistent, and periodic. Aperiodic CSI-RS transmissions are generally triggered by UL DCI (i.e., DCI format 0_1 ​​and DCI format 0_2).

[0083] CSI Framework in NR

[0084] In NR, a UE may be configured with multiple CSI reporting settings (each represented by the upper layer parameter CSI-ReportConfig with an associated identity ReportConfigID) and multiple CSI resource settings (each represented by the upper layer parameter CSI-ResourceConfig with an associated identity CSI-ResourceConfigId). Each CSI resource setting may include multiple CSI resource sets (each represented by the upper layer parameter NZP-CSI-RS-ResourceSet with an associated identity NZP-CSI-RS-ResourceSetId for channel measurements or by the upper layer parameter CSI-IM-ResourceSet with an associated identity CSI-IM-ResourceSetId for interference measurements), and each NZP CSI-RS resource set for channel measurements may include up to 8 NZP CSI-RS resources. For each CSI reporting setting, the UE feeds back a set of CSI, which may include one or more of a CSI-RS resource indicator (CRI), RI, PMI, and CQI per CW, depending on the configured reporting amount.

[0085] For each CSI reporting setting, it includes one or more of the following information: CSI resource setting for channel measurements based on NZP CSI-RS resources (represented by higher layer parameter resourcesForChannelMeasurement) CSI resource setting for interference measurement based on CSI-IM resources (represented by higher layer parameter csi-IM-ResourcesForInterference) Optionally, CSI resource setting for interference measurement based on NZP CSI-RS resources (represented by higher layer parameter nzp-CSI-RS-ResourcesForInterference) Time domain behavior, i.e. periodic, semi-persistent or aperiodic reporting (represented by the higher layer parameter reportConfigType) Frequency granularity, i.e. wideband or subband The CSI parameters to be reported, such as RI, PMI, CQI, L1RSRP / L1_SINR and CRI, in case of multiple NZP CSI-RS resources in a resource set, are used for channel measurements (represented by the higher layer parameter reportQuantity, such as "cri-RI-PMI-CQI", "cri-RSRP" or "ssb-Index-RSRP"). Codebook type, if reported, i.e. type I or II, and codebook subset restrictions Measurement Limits

[0086] For periodic and semi-static CSI reporting, only one NZP CSI-RS resource set may be configured for channel measurements and one CSI-IM resource set may be configured for interference measurements. For aperiodic CSI reporting, the CSI resource setting for channel measurements may include two or more NZP CSI-RS resource sets for channel measurements. If the CSI resource setting for channel measurements includes multiple NZP CSI-RS resource sets for aperiodic CSI reporting, only one NZP CSI-RS resource set may be selected and indicated to the UE. For aperiodic CSI reporting, a list of trigger states (given by higher layer parameter CSI-AperiodicTriggerStateList). Each trigger state in CSI-AperiodicTriggerStateList includes a list of associated CSI-ReportConfigs indicating resource set IDs for the channel and, optionally, for interference. For a UE configured with higher layer parameter CSI-AperiodicTriggerStateList, if a resource setting linked to a CSI-ReportConfig has multiple aperiodic resource sets, only one of the aperiodic CSI-RS resource sets from the resource setting is relevant for the trigger state and the UE is higher layer configured per trigger state per resource setting to select one NZP CSI-RS resource set from the resource setting.

[0087] When more than one NZP CSI-RS resource is included in a selected NZP CSI-RS resource set for channel measurement, a CSI-RS resource indicator (CRI), along with the RI, PMI and CQI associated with the selected NZP CSI-RS resource, is reported by the UE to indicate to the gNB regarding one selected NZP CSI-RS resource in the resource set. This type of CSI assumes that the PDSCH is transmitted from a single transmission reception point (TRP), and the CSI is also referred to as single-TRP CSI.

[0088] Existing NR UE behavior when aperiodic CSI-RS collides with PDSCH

[0089] The following UE behavior is specified in the existing NR specification in TS38.214 with respect to aperiodic CSI-RS colliding with PDSCH:

[0090] If the scheduling offset between the last symbol of the PDCCH carrying the triggering DCI and the first symbol of the aperiodic CSI-RS resource is less than the UE reporting threshold beamSwitchTiming, as specified in [TS38.306], If a PDSCH with the indicated TCI state is in the same symbol as a CSI-RS, where the PDSCH is scheduled with a scheduling offset greater than or equal to the threshold timeDurationForQCL, the UE shall apply the QCL assumption for the PDSCH also when receiving aperiodic CSI-RS. Otherwise, when receiving aperiodic CSI-RS, the UE applies the QCL hypothesis used for the CORESET associated to the monitored search space with the lowest controlResourceSetId in the latest slot in which one or more CORESETs in the active BWP of the serving cell are monitored.

[0091] Currently, several challenges exist. The existing NR standard specifies the UE behavior when aperiodic CSI-RS collides with PDSCH when PDSCH is indicated in a single TCI state. How the UE behaves (i.e., what QCL assumptions the UE makes) to receive aperiodic CSI-RS when the aperiodic CSI-RS collides with PDSCH(s) indicated in two TCI states in DCI is not specified in the current NR specification, and this is an open issue that needs to be resolved. In particular, this UE behavior is not specified when PDSCH uses one of the following schemes: single PDCCH-based NC-JT schemes, "FDMSchemeA", "FDMSchemeB", "TDMSchemeA".

[0092] Systems and methods are provided for determining a transmission configuration indication (TCI) state for an aperiodic (AP) channel state information reference signal (CSI-RS) that overlaps with a physical downlink shared channel (PDSCH) transmission. In some embodiments, a method implemented by a wireless device for determining a TCI state for receiving one or more AP CSI-RS includes one or more of: receiving one or more AP CSI-RS in the same symbol(s) as a downlink transmission(s) scheduled by a DCI having two TCI states indicated in the DCI; receiving triggering of the one or more AP CSI-RS at a scheduling offset between a last symbol of a PDCCH carrying the triggering DCI and a first symbol of an AP CSI-RS resource, where the scheduling offset is less than a wireless device reporting threshold; and determining that the downlink transmission is scheduled according to one of the group consisting of "TDMSchemeA", "FDMSchemeA", "FDMSchemeB", and a scheme in which different sets of layers of a downlink transmission are received in different TCI states. In some embodiments, optionally, the wireless device applies QCL assumptions for PDSCH transmission opportunities when receiving the AP CSI-RS.

[0093] 13 illustrates a method implemented by a wireless device for determining a TCI state for receiving one or more AP CSI-RS. In some embodiments, the wireless device implements one or more of: receiving one or more AP CSI-RS in the same symbol(s) as a downlink transmission(s) scheduled by a DCI with two TCI states indicated in the DCI (step 1300); receiving triggering of one or more AP CSI-RS at a scheduling offset between a last symbol of a PDCCH carrying the triggering DCI and a first symbol of an AP CSI-RS resource, where the scheduling offset is less than a wireless device reporting threshold (step 1302); and determining that the downlink transmission is scheduled according to one of the group consisting of “TDMSchemeA”, “FDMSchemeA”, “FDMSchemeB”, and a scheme in which different sets of layers of a downlink transmission are received in different TCI states (step 1304). In some embodiments, depending on the situation, the wireless device applies a QCL assumption for the PDSCH transmission opportunity when receiving the AP CSI-RS (step 1306). In some embodiments, this specifies the UE behavior (i.e., what QCL assumption the UE makes) for receiving the aperiodic CSI-RS when it collides with the PDSCH when the PDSCH is indicated in two TCI states. One benefit is that the proposed solution specifies with which QCL characteristics the colliding aperiodic CSI-RS should be received, which was not specified in NR before. With the proposed solution, the aperiodic CSI-RS can be flexibly triggered in overlapping symbols with the PDSCH scheduled according to one of the single PDCCH-based NC-JT schemes "FDMSchemeA", "FDMSchemeB", and "TDMSchemeA".

[0094] 14 illustrates a method implemented by a base station for indicating a TCI state for receiving one or more AP CSI-RS. In some embodiments, the base station performs one or more of the following: transmitting one or more AP CSI-RS to a wireless device in the same symbol(s) as a downlink transmission(s) scheduled by a DCI with two TCI states indicated in the DCI (step 1400); triggering one or more AP CSI-RS at a scheduling offset between the last symbol of a PDCCH carrying a triggering DCI and the first symbol of an AP CSI-RS resource, where the scheduling offset is less than a wireless device reporting threshold (step 1402); and scheduling the downlink transmission according to one of the group consisting of "TDMSchemeA", "FDMSchemeA", "FDMSchemeB", and a scheme in which different sets of layers of a downlink transmission are received in different TCI states (step 1404). In some embodiments, depending on the situation, the base station assumes that the wireless device applies a QCL assumption for the PDSCH transmission opportunity when receiving the AP CSI-RS (step 1406). In some embodiments, this specifies the UE behavior (i.e., what QCL assumption the UE makes) for receiving the aperiodic CSI-RS when it collides with the PDSCH when the PDSCH is indicated in two TCI states. One benefit is that the proposed solution specifies with which QCL characteristics the colliding aperiodic CSI-RS should be received, which was not specified in NR before. With the proposed solution, the aperiodic CSI-RS can be flexibly triggered in overlapping symbols with the PDSCH scheduled according to one of the single PDCCH-based NC-JT schemes "FDMSchemeA", "FDMSchemeB", and "TDMSchemeA".

[0095] Embodiment 1 for a scenario where an AP CSI-RS collides with a PDSCH scheduled according to "TDMSchemeA" and the scheduling offset is above a threshold.

[0096] In this embodiment, the UE is configured to receive the PDSCH according to “TDMSchemeA” and is indicated with two TCI states in the DCI, where a first indicated TCI state applies to PDSCH transmission opportunity 1 (denoted as PDSCH1) and a second indicated TCI state applies to PDSCH transmission opportunity 2 (denoted as PDSCH2). This corresponds to the case where the scheduling offset from the last symbol of the PDCCH carrying the DCI to the first symbol of PDSCH1 is greater than or equal to a threshold value timeDurationForQCL.

[0097] Furthermore, in this embodiment, an aperiodic CSI-RS (AP CSI-RS) is triggered to the UE by another DCI with a scheduling offset between the last symbol of the PDCCH carrying the triggering DCI (i.e., the DCI that triggers the AP CSI-RS) and the first symbol of the aperiodic CSI-RS resource that is smaller than the UE reporting threshold beamSwitchTiming. In this case, there are two possibilities shown in Figure 15, which illustrates a first example of embodiment 1 considering AP CSI-RS collision with PDSCH scheduled according to "TDMSchemeA".

[0098] 15A, when the AP CSI-RS is in the same symbol as PDSCH1, the UE applies the QCL assumption of PDSCH1 (given by the first indicated TCI state in the DCI) when receiving the AP CSI-RS. In other words, the UE receives the AP CSI-RS using the same receive beam as that used to receive PDSCH1, whose spatial QCL characteristics are given by the first indicated TCI state in the DCI.

[0099] As shown in Figure 15B, when the AP CSI-RS is in the same symbol as PDSCH2, the UE applies the QCL assumption of PDSCH2 (given by the second indicated TCI state in the DCI) when receiving the AP CSI-RS. In other words, the UE receives the AP CSI-RS using the same receive beam as that used to receive PDSCH2, whose spatial QCL characteristics are given by the second indicated TCI state in the DCI.

[0100] There is also a third possibility shown in Figure 16, which illustrates a second example of embodiment 1 considering AP CSI-RS collision with PDSCH scheduled according to "TDMSchemeA". As shown in the figure, in this third possibility, the AP CSI-RS overlaps with both PDSCH1 and PDSCH2 symbols. In this case, since the CSI-RS of a single AP CSI-RS resource is transmitted from one TRP, it is not possible to receive the CSI-RS of a single AP CSI-RS resource using two different QCL assumptions, and the UE considers this as an error case and drops the AP CSI-RS (i.e., does not receive the AP CSI-RS).

[0101] Embodiment 2 for a scenario where an AP CSI-RS collides with a PDSCH scheduled according to "TDMSchemeA" and one scheduling offset is below a threshold.

[0102] In this embodiment, the UE is configured to receive the PDSCH according to "TDMSchemeA" and is indicated with two TCI states in the DCI. In this case, the scheduling offset from the last symbol of the PDCCH to the first symbol of PDSCH1 is less than a threshold timeDurationForQCL, while the scheduling offset from the last symbol of the PDCCH to the first symbol of PDSCH2 is greater than or equal to the threshold. In this case, a first default TCI state is applied to PDSCH1 and a second indicated TCI state is applied to PDSCH2. The default TCI state for the PDSCH is given by the TCI state corresponding to the lowest codepoint among the TCI codepoints containing two different TCI states, according to the NR Rel-16 specifications. Thus, the first default TCI state is defined as the first of the two different TCI states corresponding to the lowest such codepoint.

[0103] Furthermore, in this embodiment, an aperiodic CSI-RS (AP CSI-RS) is triggered to the UE by another DCI with a scheduling offset between the last symbol of the PDCCH carrying the triggering DCI and the first symbol of the aperiodic CSI-RS resource that is smaller than a threshold, such as the UE reporting threshold beamSwitchTiming. In this case, there are two possibilities shown in Figure 17, which illustrates a first example of embodiment 2 considering AP CSI-RS collision with PDSCH scheduled according to "TDMSchemeA".

[0104] 17A, when the AP CSI-RS is in the same symbol as PDSCH1, the UE applies the QCL assumption of PDSCH1 (given by the first default TCI state) when receiving the AP CSI-RS. In other words, the UE receives the AP CSI-RS using the same receive beam as that used to receive PDSCH1, whose spatial QCL characteristics are given by the first default TCI state.

[0105] As shown in Figure 17B, when the AP CSI-RS is in the same symbol as PDSCH2, the UE applies the QCL assumption of PDSCH2 (given by the second indicated TCI state in the DCI) when receiving the AP CSI-RS. In other words, the UE receives the AP CSI-RS using the same receive beam as that used to receive PDSCH2, whose spatial QCL characteristics are given by the second indicated TCI state in the DCI.

[0106] There is also a third possibility shown in Figure 18, which illustrates a second example of embodiment 2 considering AP CSI-RS collision with PDSCH scheduled according to "TDMSchemeA". As shown in the figure, in this third possibility, the AP CSI-RS overlaps between both PDSCH1 and PDSCH2 symbols. In this case, since it is not possible to receive different CSI-RS on a single AP CSI-RS resource using two different QCL assumptions, the UE drops the AP CSI-RS (i.e., does not receive the AP CSI-RS).

[0107] Embodiment 3 for a scenario where an AP CSI-RS collides with a PDSCH scheduled according to "TDMSchemeA" and both scheduling offsets are below a threshold.

[0108] In this embodiment, the UE is configured to receive the PDSCH according to "TDMSchemeA" and is indicated by two TCI states in the DCI, where the scheduling offset from the last symbol of the PDCCH to the first symbol of PDSCH1 is smaller than a threshold timeDurationForQCL and / or the scheduling offset from the last symbol of the PDCCH to the first symbol of PDSCH2 is smaller than a threshold timeDurationForQCL.

[0109] In this case, the first default TCI state is applied to PDSCH1 and the second default TCI state is applied to PDSCH2. The default TCI state for the PDSCH is given by the TCI state that corresponds to the lowest codepoint among the TCI codepoints that contain two different TCI states, according to the NR Rel-16 specifications. Thus, the first default TCI state and the second default TCI state correspond to the first and second of the two different TCI states that correspond to the lowest such codepoint, respectively.

[0110] Furthermore, in this embodiment, aperiodic CSI-RS (AP CSI-RS) is triggered to the UE with a scheduling offset between the last symbol of the PDCCH carrying the triggering DCI and the first symbol of the aperiodic CSI-RS resource that is smaller than the UE reporting threshold beamSwitchTiming. In this case, there are two possibilities shown in Figure 19, which illustrates a first example of embodiment 3 considering AP CSI-RS collision with PDSCH scheduled according to "TDMSchemeA".

[0111] 19A, when the AP CSI-RS is in the same symbol as PDSCH1, the UE applies the QCL assumption of PDSCH1 (given by the first default TCI state) when receiving the AP CSI-RS. In other words, the UE receives the AP CSI-RS using the same receive beam as that used to receive PDSCH1, whose spatial QCL characteristics are given by the first default TCI state.

[0112] As shown in Figure 19B, when the AP CSI-RS is in the same symbol as PDSCH2, the UE applies the QCL assumption of PDSCH2 (given by the second default TCI state) when receiving the AP CSI-RS. In other words, the UE receives the AP CSI-RS using the same receive beam as that used to receive PDSCH2, whose spatial QCL characteristics are given by the second default TCI state.

[0113] There is also a third possibility shown in Figure 20, which illustrates a second example of embodiment 3 considering AP CSI-RS collision with PDSCH scheduled according to "TDMSchemeA". As shown in the figure, in this third possibility, the AP CSI-RS overlaps between both PDSCH1 and PDSCH2 symbols. In this case, since it is not possible to receive different CSI-RS on a single AP CSI-RS resource using two different QCL assumptions, the UE drops the AP CSI-RS (i.e., does not receive the AP CSI-RS).

[0114] Embodiment 4 for a scenario in which an AP CSI-RS collides with a PDSCH scheduled according to a single PDCCH-based NC-JT scheme and the scheduling offset is above a threshold.

[0115] In this embodiment, the UE is configured to receive the PDSCH according to the single PDCCH-based NC-JT scheme and is indicated with two TCI states in the DCI, where the two indicated TCI states are used to receive different sets of layers corresponding to the PDSCH (i.e., a first set of layers corresponds to a first TCI state and a second set of layers corresponds to a second TCI state). This corresponds to the case where the scheduling offset from the last symbol of the PDCCH to the first symbol of the PDSCH is greater than or equal to a threshold value timeDurationForQCL.

[0116] Furthermore, in some cases, the aperiodic CSI-RS (AP CSI-RS) is triggered to the UE by another DCI with a scheduling offset between the last symbol of the PDCCH carrying the triggering DCI and the first symbol of the aperiodic CSI-RS resource that is smaller than the UE reporting threshold beamSwitchTiming. Figure 21 illustrates a first example of embodiment 4 considering AP CSI-RS collision with a PDSCH scheduled according to the single PDCCH-based NC-JT scheme, where a first TCI state is assumed for the AP CSI-RS. The aperiodic CSI-RS overlaps with the PDSCH symbols as shown in Figure 21.

[0117] In this case, when the AP CSI-RS is in the same symbol as the PDSCH as shown in Figure 21, the UE applies the QCL assumption given by the first indicated TCI state in the DCI for the PDSCH when receiving the AP CSI-RS. In other words, the UE receives the AP CSI-RS using the same receive beam as that used to receive the PDSCH, whose spatial QCL characteristics are given by the first indicated TCI state in the DCI.

[0118] In the second case, two AP CSI-RS (e.g., each AP CSI-RS transmitted from a different TRP) are triggered to the UE with a scheduling offset between the last symbol of the PDCCH carrying the triggering DCI and the first symbol(s) of the aperiodic CSI-RS resource that is smaller than the UE reporting threshold beamSwitchTiming. Figure 22 illustrates a second example of the fourth embodiment considering AP CSI-RS collision with a PDSCH scheduled according to a single PDCCH-based NC-JT scheme, in which a first TCI state and a second TCI state are assumed for the first AP CSI-RS and the second AP CSI-RS, respectively. The two aperiodic CSI-RS overlap with the PDSCH symbols as shown in Figure 22.

[0119] In this case, for the first AP CSI-RS, the UE applies the QCL assumption given by the first indicated TCI state in the DCI for the PDSCH when receiving the first AP CSI-RS. In other words, the UE receives the first AP CSI-RS using the same receive beam as that used to receive the PDSCH, whose spatial QCL characteristics are given by the first indicated TCI state in the DCI.

[0120] For the second AP CSI-RS, the UE applies the QCL assumption given by the second indicated TCI state in the DCI for the PDSCH when receiving the second AP CSI-RS. In other words, the UE receives the second AP CSI-RS using the same receive beam as that used to receive the PDSCH, whose spatial QCL characteristics are given by the second indicated TCI state in the DCI.

[0121] The first AP CSI-RS resource and the second AP CSI-RS resource are specified using either the CSI-RS resource ID or the CSI-RS resource set ID (i.e., NZP-CSI-RS-ResourceSetId) to which the AP CSI-RS resource belongs. For example, if two AP CSI-RS resources are in different CSI-RS resource set IDs, the AP CSI-RS resource with the smallest NZP-CSI-RS-ResourceSetId is the first AP CSI-RS resource and the AP CSI-RS resource with the largest NZP-CSI-RS-ResourceSetId is the second AP CSI-RS resource. Similar specification of the first AP CSI-RS resource and the second AP CSI-RS resource may be achieved by using the CSI-RS resource ID instead of the CSI-RS resource set ID.

[0122] This embodiment is written from the perspective of a PDSCH scheduled according to the single PDCCH-based NC-JT scheme, but it can be easily extended to a PDSCH scheduled via either "FDMSchemeA" or "FDMSchemeB".

[0123] Embodiment 5 for a scenario in which an AP CSI-RS collides with a PDSCH scheduled according to a single PDCCH-based NC-JT scheme and the scheduling offset is below a threshold.

[0124] In this embodiment, the UE is configured to receive the PDSCH according to the single PDCCH-based NC-JT scheme and is indicated with two TCI states in the DCI, where two default TCI states are used to receive different layers corresponding to the PDSCH. This corresponds to the case where the scheduling offset from the last symbol of the PDCCH to the first symbol of the PDSCH is smaller than a threshold timeDurationForQCL. The default TCI state for the PDSCH is given by the TCI state corresponding to the lowest codepoint among the TCI codepoints containing two different TCI states according to the NR Rel-16 specifications.

[0125] Furthermore, in some cases, aperiodic CSI-RS (AP CSI-RS) is triggered to the UE with a scheduling offset between the last symbol of the PDCCH carrying the triggering DCI and the first symbol of the aperiodic CSI-RS resource that is smaller than the UE reporting threshold beamSwitchTiming. Figure 23 illustrates a first example of embodiment 5 considering AP CSI-RS collision with PDSCH scheduled according to the single PDCCH-based NC-JT scheme, in which a first default TCI state is assumed for AP CSI-RS. The aperiodic CSI-RS overlaps with the PDSCH symbols as shown in Figure 23.

[0126] In this case, when the AP CSI-RS is in the same symbol as the PDSCH as shown in Figure 23, the UE applies the QCL assumption given by the first default TCI state in the DCI for the PDSCH when receiving the AP CSI-RS. In other words, the UE receives the AP CSI-RS using the same receive beam as that used for receiving the PDSCH, whose spatial QCL characteristics are given by the first default TCI state.

[0127] In the second case, two AP CSI-RS (e.g., each AP CSI-RS transmitted from a different TRP) are triggered to the UE with a scheduling offset between the last symbol of the PDCCH carrying the triggering DCI and the first symbol(s) of the aperiodic CSI-RS resource that is smaller than the UE reporting threshold beamSwitchTiming. Figure 24 illustrates a second example of the fifth embodiment considering AP CSI-RS collision with a PDSCH scheduled according to a single PDCCH-based NC-JT scheme, in which a first default TCI state and a second default TCI state are assumed for the first AP CSI-RS and the second AP CSI-RS, respectively. The two aperiodic CSI-RS overlap with the PDSCH symbols as shown in Figure 24.

[0128] In this case, for the first AP CSI-RS, the UE applies the QCL assumption given by the first default TCI state for the PDSCH when receiving the first AP CSI-RS. In other words, the UE receives the first AP CSI-RS using the same receive beam as that used to receive the PDSCH, whose spatial QCL characteristics are given by the first default TCI state in the DCI.

[0129] For the second AP CSI-RS, the UE applies the QCL assumption given by the second default TCI state for the PDSCH when receiving the second AP CSI-RS. In other words, the UE receives the second AP CSI-RS using the same receive beam as that used to receive the PDSCH, whose spatial QCL characteristics are given by the second indicated TCI state in the DCI.

[0130] The first AP CSI-RS resource and the second AP CSI-RS resource are specified using either the CSI-RS resource ID or the CSI-RS resource set ID (i.e., NZP-CSI-RS-ResourceSetId) to which the AP CSI-RS resource belongs. For example, if two AP CSI-RS resources are in different CSI-RS resource set IDs, the AP CSI-RS resource with the smallest NZP-CSI-RS-ResourceSetId is the first AP CSI-RS resource and the AP CSI-RS resource with the largest NZP-CSI-RS-ResourceSetId is the second AP CSI-RS resource. Similar specification of the first AP CSI-RS resource and the second AP CSI-RS resource may be achieved by using the CSI-RS resource ID instead of the CSI-RS resource set ID.

[0131] This embodiment is written from the perspective of a PDSCH scheduled according to the single PDCCH-based NC-JT scheme, but it can be easily extended to a PDSCH scheduled via either "FDMSchemeA" or "FDMSchemeB".

[0132] FIG. 25 is a schematic block diagram of a radio access node 2500 according to some embodiments of the disclosure. Optional features are represented by dotted boxes. The radio access node 2500 may be, for example, a base station 402 or 406, or a network node implementing all or a portion of the functionality of a base station 402 or gNB described herein. As shown, the radio access node 2500 includes a control system 2502 including one or more processors 2504 (e.g., a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), etc.), a memory 2506, and a network interface 2508. The one or more processors 2504 are also referred to herein as processing circuits. Additionally, the radio access node 2500 may include one or more radio units 2510, each including one or more transmitters 2512 and one or more receivers 2514 coupled to one or more antennas 2516. The radio unit 2510 may be referred to as or part of a radio interface circuit. In some embodiments, the radio unit(s) 2510 are external to the control system 2502 and are connected to the control system 2502, for example, via a wired connection (e.g., optical cable). However, in some other embodiments, the radio unit(s) 2510 and potentially the antenna(s) 2516 are integrated together with the control system 2502. The one or more processors 2504 operate to provide one or more functions of the radio access node 2500 described herein. In some embodiments, the function(s) are implemented in software, for example, stored in the memory 2506 and executed by the one or more processors 2504.

[0133] 26 is a schematic block diagram illustrating a virtualized embodiment of a radio access node 2500 according to some embodiments of the present disclosure. This description is equally applicable to other types of network nodes. Furthermore, other types of network nodes may have a similar virtualized architecture. Again, optional features are represented by dotted boxes.

[0134] A "virtualized" radio access node, as used herein, is an implementation of a radio access node 2500 in which at least a portion of the functionality of the radio access node 2500 is implemented as virtual component(s) (e.g., via virtual machine(s) executing on physical processing node(s) in network(s)). As shown, in this example, the radio access node 2500 may include a control system 2502 and / or one or more radio units 2510, as described above. The control system 2502 may be connected to the radio unit(s) 2510 via, for example, an optical cable or the like. The radio access node 2500 includes one or more processing nodes 2600 coupled to or included as part of the network(s) 2602. If present, the control system 2502 or the radio unit(s) are connected to the processing node(s) 2600 via the network 2602. Each processing node 2600 includes one or more processors 2604 (e.g., a CPU, ASIC, FPGA, etc.), a memory 2606, and a network interface 2608.

[0135] In this example, the functions 2610 of the radio access node 2500 described herein are implemented in one or more processing nodes 2600 or distributed across one or more processing nodes 2600 and the control system 2502 and / or radio unit(s) 2510 in any desired manner. In some particular embodiments, some or all of the functions 2610 of the radio access node 2500 described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s) 2600. As will be appreciated by those skilled in the art, additional signaling or communication between the processing node(s) 2600 and the control system 2502 is used to perform at least some of the desired functions 2610. Notably, in some embodiments, the control system 2502 may not be included, in which case the radio unit(s) 2510 communicates directly with the processing node(s) 2600 via an appropriate network interface(s).

[0136] In some embodiments, a computer program is provided that includes instructions that, when executed by at least one processor, cause the at least one processor to perform functions of the radio access node 2500 or a node (e.g., processing node 2600) implementing one or more of the functions 2610 of the radio access node 2500 in a virtual environment in accordance with any of the embodiments described herein. In some embodiments, a carrier is provided that comprises the computer program product described above. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as a memory).

[0137] 27 is a schematic block diagram of a radio access node 2500 according to some other embodiments of the present disclosure. The radio access node 2500 includes one or more modules 2700, each of which is implemented in software. The module(s) 2700 provide the functionality of the radio access node 2500 described herein. This description is equally applicable to the processing node 2600 of FIG. 26, where the module 2700 may be implemented in one of the processing nodes 2600 or distributed across multiple processing nodes 2600 and / or distributed across the processing node(s) 2600 and the control system 2502.

[0138] 28 is a schematic block diagram of a wireless communication device 2800 according to some embodiments of the present disclosure. As shown, the wireless communication device 2800 includes one or more processors 2802 (e.g., CPU, ASIC, FPGA, etc.), a memory 2804, and one or more transceivers 2806, each including one or more transmitters 2808 and one or more receivers 2810 coupled to one or more antennas 2812. The transceiver(s) 2806 includes a radio front-end circuit connected to the antenna(s) 2812 configured to condition signals communicated between the antenna(s) 2812 and the processor(s) 2802, as will be appreciated by those skilled in the art. The processor 2802 is also referred to herein as a processing circuit. The transceiver 2806 is also referred to herein as a radio circuit. In some embodiments, the functionality of the wireless communication device 2800 described above may be implemented fully or partially in software, e.g., stored in memory 2804 and executed by processor(s) 2802. It should be noted that the wireless communication device 2800 may include additional components not shown in FIG. 28, such as, for example, one or more user interface components (e.g., input / output interfaces including a display, buttons, a touch screen, a microphone, speaker(s), etc., and / or any other components for enabling input of information into and / or output of information from the wireless communication device 2800), a power supply (e.g., a battery and associated power circuitry), etc.

[0139] In some embodiments, a computer program is provided that includes instructions that, when executed by at least one processor, cause the at least one processor to perform the functions of the wireless communication device 2800 in accordance with any of the embodiments described herein. In some embodiments, a carrier is provided that comprises the computer program product described above. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer-readable storage medium (e.g., a non-transitory computer-readable medium such as a memory).

[0140] 29 is a schematic block diagram of a wireless communication device 2800 according to some other embodiments of the present disclosure. The wireless communication device 2800 includes one or more modules 2900, each of which is implemented in software. The module(s) 2900 provide the functionality of the wireless communication device 2800 described herein.

[0141] Referring to Figure 30, according to one embodiment, a communication system includes a communication network 3000, such as a 3GPP type cellular network, comprising an access network 3002, such as a RAN, and a core network 3004. The access network 3002 comprises a number of base stations 3006A, 3006B, 3006C, such as Node Bs, eNBs, gNBs, or other types of wireless access points (APs), each defining a corresponding coverage area 3008A, 3008B, 3008C. Each base station 3006A, 3006B, 3006C is connectable to the core network 3004 via a wired or wireless connection 3010. A first UE 3012 located in the coverage area 3008C is configured to wirelessly connect to or be paged by the corresponding base station 3006C. A second UE 3014 in the coverage area 3008A can wirelessly connect to the corresponding base station 3006A. Although multiple UEs 3012, 3014 are shown in this example, the disclosed embodiments are equally applicable to situations where only one UE is in the coverage area or connected to the corresponding base station 3006.

[0142] The communication network 3000 is itself connected to a host computer 3016, which may be embodied in hardware and / or software of a standalone server, a cloud-implemented server, a distributed server, or as a processing resource in a server farm. The host computer 3016 may be owned or under the control of a service provider, or may be operated by or on behalf of the service provider. The connections 3018 and 3020 between the communication network 3000 and the host computer 3016 may extend directly from the core network 3004 to the host computer 3016, or may proceed through an optional intermediate network 3022. The intermediate network 3022 may be one of a public network, a private network, or a hosted network, or a combination of two or more of them, and the intermediate network 3022 may be a backbone network or the Internet, if any, and in particular the intermediate network 3022 may comprise two or more sub-networks (not shown).

[0143] The communication system of FIG. 30 as a whole enables connectivity between the connected UEs 3012, 3014 and the host computer 3016. The connectivity may be described as an over-the-top (OTT) connection 3024. The host computer 3016 and the connected UEs 3012, 3014 are configured to communicate data and / or signaling via the OTT connection 3024 using the access network 3002, the core network 3004, any intermediate networks 3022, and possible further infrastructure (not shown) as intermediaries. The OTT connection 3024 may be transparent in the sense that the participating communication devices through which the OTT connection 3024 passes are unaware of the routing of the uplink and downlink communications. For example, the base station 3006 may not be or need not be informed of the past routing of incoming downlink communications involving data originating from the host computer 3016 to be forwarded (e.g., handed over) to the connected UE 3012. Similarly, the base station 3006 does not need to be aware of the future routing of outgoing uplink communications originating from the UE 3012 and destined for the host computer 3016 .

[0144] Next, an exemplary implementation of the UE, base station, and host computer described in the previous paragraph according to an embodiment will be described with reference to FIG. 31. In the communication system 3100, the host computer 3102 comprises hardware 3104 including a communication interface 3106 configured to set up and maintain wired or wireless connections with interfaces of different communication devices of the communication system 3100. The host computer 3102 further comprises a processing circuit 3108, which may have storage and / or processing capabilities. In particular, the processing circuit 3108 may comprise one or more programmable processors, ASICs, FPGAs, or combinations thereof (not shown) adapted to execute instructions. The host computer 3102 further comprises software 3110, which is stored in or accessible by the host computer 3102 and executable by the processing circuit 3108. The software 3110 includes a host application 3112. The host application 3112 may be operable to provide services to a remote user, such as the UE 3114 connecting via an OTT connection 3116 that terminates at the UE 3114 and the host computer 3102. In providing services to the remote user, the host application 3112 may provide user data that is transmitted using the OTT connection 3116.

[0145] The communication system 3100 further includes a base station 3118 provided in the communication system, the base station 3118 comprising hardware 3120 enabling the base station 3118 to communicate with the host computer 3102 and the UE 3114. The hardware 3120 may include a communication interface 3122 for setting up and maintaining wired or wireless connections with interfaces of different communication devices of the communication system 3100, as well as a wireless interface 3124 for setting up and maintaining at least a wireless connection 3126 with a UE 3114 located in a coverage area (not shown in FIG. 31) served by the base station 3118. The communication interface 3122 may be configured to facilitate a connection 3128 to the host computer 3102. The connection 3128 may be direct or the connection 3128 may pass through a core network (not shown in FIG. 31) of the communication system and / or one or more intermediate networks outside the communication system. In the illustrated embodiment, the hardware 3120 of the base station 3118 further includes processing circuitry 3130, which may comprise one or more programmable processors, ASICs, FPGAs, or combinations thereof (not shown) adapted to execute instructions. The base station 3118 further has software 3132 stored internally or accessible via an external connection.

[0146] The communication system 3100 further includes the UE 3114 already mentioned. The hardware 3134 of the UE 3114 may include a wireless interface 3136 configured to set up and maintain a wireless connection 3126 with a base station serving a coverage area in which the UE 3114 is currently located. The hardware 3134 of the UE 3114 further includes a processing circuit 3138, which may comprise one or more programmable processors, ASICs, FPGAs, or combinations thereof (not shown) adapted to execute instructions. The UE 3114 further includes software 3140 stored in or accessible by the UE 3114 and executable by the processing circuit 3138. The software 3140 includes a client application 3142. The client application 3142, with the support of the host computer 3102, may be operable to provide services to a human or non-human user via the UE 3114. At the host computer 3102, a running host application 3112 may communicate with a running client application 3142 via an OTT connection 3116 that terminates at the UE 3114 and the host computer 3102. In providing services to a user, the client application 3142 may receive request data from the host application 3112 and provide user data in response to the request data. The OTT connection 3116 may transfer both the request data and the user data. The client application 3142 may interact with the user to generate the user data that the client application 3142 provides.

[0147] It should be noted that the host computer 3102, base station 3118, and UE 3114 shown in Figure 31 may be similar or equivalent to the host computer 3016, one of the base stations 3006A, 3006B, 3006C, and one of the UEs 3012, 3014, respectively, of Figure 30. That is, the inner workings of these entities may be as shown in Figure 31, and separately, the surrounding network topology may be that of Figure 30.

[0148] In Figure 31, the OTT connection 3116 is depicted abstractly to show communication between the host computer 3102 and the UE 3114 via the base station 3118, without explicit reference to intermediary devices and the exact routing of messages through these devices. The network infrastructure may determine the routing, which may be configured to be hidden from the UE 3114 or from the service provider operating the host computer 3102, or both. While the OTT connection 3116 is active, the network infrastructure may also make decisions to dynamically change the routing (e.g., based on load balancing considerations or reconfiguration of the network).

[0149] The wireless connection 3126 between the UE 3114 and the base station 3118 follows the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of the OTT service provided to the UE 3114 using the OTT connection 3116 of which the wireless connection 3126 forms the last segment. More precisely, the teachings of these embodiments may improve, for example, data rates, latency, power consumption, etc., thereby providing benefits such as, for example, reduced user latency, relaxed restrictions on file sizes, better responsiveness, extended battery life, etc.

[0150] Measurement procedures may be provided for the purpose of monitoring data rates, latency, and other factors that one or more embodiments improve upon. There may further be an optional network function for reconfiguring the OTT connection 3116 between the host computer 3102 and the UE 3114 in response to fluctuations in the measurement results. The measurement procedures and / or the network function for reconfiguring the OTT connection 3116 may be implemented in the software 3110 and hardware 3104 of the host computer 3102 or in the software 3140 and hardware 3134 of the UE 3114, or both. In some embodiments, sensors (not shown) may be deployed in or in association with the communication devices through which the OTT connection 3116 passes, and the sensors may participate in the measurement procedures by providing values ​​of the monitored quantities exemplified above, or other physical quantities from which the software 3110, 3140 may calculate or estimate the monitored quantities. The reconfiguration of the OTT connection 3116 may include message formats, retransmission settings, preferred routing, etc., and the reconfiguration need not affect the base station 3118, and the reconfiguration may be unknown or imperceptible to the base station 3118. Such procedures and functions may be known and practiced in the art. In some embodiments, the measurements may involve proprietary UE signaling that facilitates the host computer 3102 measurements of throughput, propagation time, latency, etc. The measurements may be implemented in that the software 3110 and 3140 cause messages, particularly empty or "dummy" messages, to be sent using the OTT connection 3116 while the software 3110 and 3140 monitors propagation times, errors, etc.

[0151] FIG. 32 is a flow chart illustrating a method implemented in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be as described with reference to FIG. 30 and FIG. 31. For simplicity of the disclosure, only drawing references to FIG. 32 are included in this section. In step 3200, the host computer provides user data. In sub-step 3202 (which may be optional) of step 3200, the host computer provides the user data by executing a host application. In step 3204, the host computer initiates a transmission carrying the user data to the UE. In step 3206 (which may be optional), the base station transmits the user data carried in the host computer initiated transmission to the UE, according to the teachings of the embodiments described throughout this disclosure. In step 3208 (which may also be optional), the UE executes a client application associated with the host application executed by the host computer.

[0152] FIG. 33 is a flow chart illustrating a method implemented in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be as described with reference to FIG. 30 and FIG. 31. For simplicity of the disclosure, only drawing references to FIG. 33 are included in this section. In step 3300 of the method, the host computer provides user data. In an optional sub-step (not shown), the host computer provides the user data by executing a host application. In step 3302, the host computer initiates a transmission carrying the user data to the UE. The transmission may go through a base station according to the teachings of the embodiments described throughout this disclosure. In step 3304 (which may be optional), the UE receives the user data carried in the transmission.

[0153] FIG. 34 is a flow chart illustrating a method implemented in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be as described with reference to FIG. 30 and FIG. 31. For simplicity of the disclosure, only drawing references to FIG. 34 are included in this section. In step 3400 (which may be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step 3402, the UE provides user data. In sub-step 3404 (which may be optional) of step 3400, the UE provides the user data by executing a client application. In sub-step 3406 (which may be optional) of step 3402, the UE executes a client application that provides the user data in response to the received input data provided by the host computer. In providing the user data, the executed client application may further take into account user input received from the user. Regardless of the particular manner in which the user data is provided, the UE initiates transmission of the user data to the host computer in sub-step 3408 (which may be optional). In method step 3410, the host computer receives user data transmitted from the UE according to the teachings of the embodiments described throughout this disclosure.

[0154] FIG. 35 is a flow chart illustrating a method implemented in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be as described with reference to FIG. 30 and FIG. 31. For simplicity of the disclosure, only drawing references to FIG. 35 are included in this section. In step 3500 (which may be optional), the base station receives user data from the UE, according to the teachings of the embodiments described throughout this disclosure. In step 3502 (which may be optional), the base station initiates transmission of the received user data to the host computer. In step 3504 (which may be optional), the host computer receives the user data carried in the transmission initiated by the base station.

[0155] Any suitable steps, methods, features, functions, or benefits disclosed herein may be implemented through one or more functional units or modules of one or more virtual devices. Each virtual device may comprise several of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessors or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), dedicated digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory, such as read-only memory (ROM), random access memory (RAM), cache memory, flash memory devices, optical storage devices, and the like. The program code stored in memory includes program instructions for implementing one or more communication and / or data communication protocols, as well as instructions for performing one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause each functional unit to perform a corresponding function according to one or more embodiments of the present disclosure.

[0156] Although the processes in the figures may indicate a particular order of operations performed by some embodiments of the present disclosure, it should be understood that such orders are exemplary (e.g., alternative embodiments may perform operations in a different order, combine some operations, overlap some operations, etc.).

[0157] Embodiment

[0158] Group A Embodiments

[0159] 13. A method implemented by a wireless device for determining a transmission configuration indication (TCI) state for receiving one or more aperiodic (AP) channel state information reference signals (CSI-RS), the method including: receiving one or more AP CSI-RS in the same symbol(s) as a downlink transmission(s) scheduled by a DCI having two TCI states indicated in the DCI (1300); receiving triggering of the one or more AP CSI-RS at a scheduling offset between a last symbol of a PDCCH carrying the triggering DCI and a first symbol of an AP CSI-RS resource (1302), the scheduling offset being less than a wireless device reporting threshold (1302); and determining that the downlink transmission is scheduled according to one of the group consisting of “TDMSchemeA”, “FDMSchemeA”, “FDMSchemeB”, and a scheme in which different sets of layers of the downlink transmission are received in different TCI states (1304).

[0160]

[0023] Embodiment 2: The method of embodiment 1, wherein the downlink transmission(s) comprise(s) Physical Downlink Shared Channel (PDSCH) transmission(s).

[0161]

[0023] Embodiment 3: The method of embodiment 1 or 2, wherein the wireless device reporting threshold comprises a beamSwitchTiming value.

[0162] Embodiment 4: The method according to any one of embodiments 1 to 3, wherein the PDSCH is scheduled according to one of the group consisting of "FDMSchemeA", "FDMSchemeB", and a scheme in which different sets of layers of the PDSCH are received in different TCI states.

[0163] Embodiment 5: The method according to any one of embodiments 1 to 4, wherein a scheduling offset from the last symbol of the PDCCH to the first symbol of the PDSCH is greater than or equal to a threshold value timeDurationForQCL.

[0164]

[0023] Embodiment 6: The method of any one of embodiments 1 to 5, further comprising: applying (1306) a quasi-colocated (QCL) assumption given by a first indicated TCI state in the DCI for the PDSCH when receiving the AP CSI-RS when the single triggered AP CSI-RS is in the same symbol as the PDSCH.

[0165] Embodiment 7: The method of any one of embodiments 1 to 6, further comprising: applying (1306) a QCL assumption given by a first indicated TCI state and a second indicated TCI state in the DCI for the PDSCH when receiving a first AP CSI-RS and a second AP CSI-RS, respectively, when the two triggered AP CSI-RS are in the same symbol as the PDSCH.

[0166] Embodiment 8: The method according to any one of embodiments 1 to 7, wherein the first triggered AP CSI-RS and the second triggered AP CSI-RS follow a classification of corresponding CSI-RS resource identifiers or a classification of corresponding CSI-RS resource set identifiers to which the two AP CSI-RSs belong.

[0167]

[0023] Embodiment 9: The method according to any one of embodiments 1 to 8, wherein a scheduling offset from the last symbol of the PDCCH to the first symbol of the PDSCH is less than a threshold timeDurationForQCL.

[0168]

[0023] Embodiment 10: The method of any one of embodiments 1 to 9, further comprising: applying (1306) a QCL assumption given by a first default TCI state for the PDSCH when receiving the AP CSI-RS when the single triggered AP CSI-RS is in the same symbol as the PDSCH.

[0169]

[0023] Embodiment 11: The method according to any one of embodiments 1 to 10, further comprising: applying (1306) a QCL assumption given by a first default TCI state and a second default TCI state for a PDSCH when receiving a first AP CSI-RS and a second AP CSI-RS, respectively, when two triggered AP CSI-RSs are in the same symbol as a PDSCH.

[0170] Embodiment 12: The method according to any one of embodiments 1 to 11, wherein the first triggered AP CSI-RS and the second triggered AP CSI-RS follow a classification of corresponding CSI-RS resource identifiers or a classification of corresponding CSI-RS resource set identifiers to which the two AP CSI-RSs belong.

[0171] Embodiment 13: The method according to any one of embodiments 1 to 12, wherein the PDSCH is scheduled according to "TDMSchemeA".

[0172]

[0036] Embodiment 14: The method according to any one of embodiments 1 to 13, wherein a scheduling offset from the last symbol of the PDCCH to the first symbol of the first PDSCH transmission opportunity is greater than or equal to a threshold value timeDurationForQCL.

[0173]

[0036] Embodiment 15: The method of any one of embodiments 1 to 14, further comprising: applying (1306) a QCL assumption given by a first indicated TCI state in the DCI for the first PDSCH transmission opportunity when receiving the AP CSI-RS when the single triggered AP CSI-RS is in the same symbol as the first PDSCH transmission opportunity.

[0174]

[0036] Embodiment 16: The method of any one of embodiments 1 to 15, further comprising: applying (1306) a QCL assumption given by a second indicated TCI state in the DCI for the second PDSCH transmission opportunity when receiving the AP CSI-RS when the single triggered AP CSI-RS is in the same symbol as the second PDSCH transmission opportunity.

[0175] Embodiment 17: The method according to any one of embodiments 1 to 16, wherein the scheduling offset from the last symbol of the PDCCH to the first symbol of the first PDSCH transmission opportunity and the scheduling offset from the last symbol of the PDCCH to the first symbol of the second PDSCH transmission opportunity are both less than a threshold timeDurationForQCL.

[0176]

[0036] Embodiment 18: The method of any one of embodiments 1 to 17, further comprising: applying (1306) a QCL assumption given by a first default TCI state in the DCI for the first PDSCH transmission opportunity when receiving the AP CSI-RS when the single triggered AP CSI-RS is in the same symbol as the first PDSCH transmission opportunity.

[0177]

[0036] Embodiment 19: The method of any one of embodiments 1 to 18, further comprising: applying (1306) a QCL assumption given by a second indicated TCI state in the DCI for the second PDSCH transmission opportunity when receiving the AP CSI-RS when the single triggered AP CSI-RS is in the same symbol as the second PDSCH transmission opportunity.

[0178]

[0036] Embodiment 20: The method of any one of embodiments 1 to 19, further comprising providing user data and forwarding the user data to the host computer via transmission to the base station.

[0179] Group B Embodiments

[0180] Embodiment 21: A method implemented by a base station for indicating a transmission configuration indication (TCI) state for receiving one or more aperiodic (AP) channel state information reference signals (CSI-RS), the method including: transmitting to a wireless device one or more AP CSI-RS in the same symbol(s) as a downlink transmission(s) scheduled by a DCI having two TCI states indicated in the DCI (1400); triggering the one or more AP CSI-RS with a scheduling offset between a last symbol of a PDCCH carrying the triggering DCI and a first symbol of an AP CSI-RS resource (1402), the scheduling offset being less than a wireless device reporting threshold (1402); and scheduling the downlink transmission according to one of the group consisting of "TDMSchemeA", "FDMSchemeA", "FDMSchemeB", and a scheme in which different sets of layers of the downlink transmission are received in different TCI states (1404).

[0181]

[0046] Embodiment 22: The method of embodiment 21, wherein the downlink transmission(s) comprise(s) Physical Downlink Shared Channel (PDSCH) transmission(s).

[0182]

[0081] Embodiment 23: The method of embodiment 21 or 22, wherein the wireless device reporting threshold comprises a beamSwitchTiming value.

[0183] Embodiment 24: The method according to any one of embodiments 21 to 23, wherein the PDSCH is scheduled according to one of the group consisting of "FDMSchemeA", "FDMSchemeB", and a scheme in which different sets of layers of the PDSCH are received in different TCI states.

[0184]

[0043] Embodiment 25: The method according to any one of embodiments 21 to 24, wherein a scheduling offset from the last symbol of the PDCCH to the first symbol of the PDSCH is greater than or equal to a threshold value timeDurationForQCL.

[0185]

[0036] Embodiment 26: The method of any one of embodiments 21 to 25, further comprising: assuming (1406) that when a single triggered AP CSI-RS is in the same symbol as the PDSCH, the wireless device applies a quasi-colocated (QCL) assumption given by a first indicated TCI state in the DCI for the PDSCH when receiving the AP CSI-RS.

[0186]

[0036] Embodiment 27: The method of any one of embodiments 21 to 26, further comprising: assuming (1406) that when two triggered AP CSI-RSs are in the same symbol as the PDSCH, the wireless device applies the QCL assumptions given by the first indicated TCI state and the second indicated TCI state in the DCI for the PDSCH when receiving the first AP CSI-RS and the second AP CSI-RS, respectively.

[0187]

[0046] Embodiment 28: The method according to any one of embodiments 21 to 27, wherein the first triggered AP CSI-RS and the second triggered AP CSI-RS follow a classification of corresponding CSI-RS resource identifiers or a classification of corresponding CSI-RS resource set identifiers to which the two AP CSI-RSs belong.

[0188]

[0041] Embodiment 29: The method according to any one of embodiments 21 to 28, wherein a scheduling offset from the last symbol of the PDCCH to the first symbol of the PDSCH is less than a threshold timeDurationForQCL.

[0189]

[0036] Embodiment 30: The method of any one of embodiments 21 to 29, further comprising: assuming (1406) that when a single triggered AP CSI-RS is in the same symbol as the PDSCH, the wireless device applies the QCL assumption given by the first default TCI state for the PDSCH when receiving the AP CSI-RS.

[0190]

[0036] Embodiment 31: The method of any one of embodiments 21 to 30, further comprising: assuming (1406) that when two triggered AP CSI-RSs are in the same symbol as a PDSCH, the wireless device applies the QCL assumptions provided by the first and second default TCI states for the PDSCH when receiving the first and second AP CSI-RSs, respectively.

[0191]

[0046] Embodiment 32: The method according to any one of embodiments 21 to 31, wherein the first triggered AP CSI-RS and the second triggered AP CSI-RS follow a classification of corresponding CSI-RS resource identifiers or a classification of corresponding CSI-RS resource set identifiers to which the two AP CSI-RSs belong.

[0192] Embodiment 33: The method according to any one of embodiments 21 to 32, wherein the PDSCH is scheduled according to "TDMSchemeA".

[0193]

[0041] Embodiment 34: The method according to any one of embodiments 21 to 33, wherein a scheduling offset from the last symbol of the PDCCH to the first symbol of the first PDSCH transmission opportunity is greater than or equal to a threshold value timeDurationForQCL.

[0194]

[0036] Embodiment 35: The method of any one of embodiments 21 to 34, further comprising: assuming (1406) that when a single triggered AP CSI-RS is in the same symbol as the first PDSCH transmission opportunity, the wireless device applies the QCL assumption given by the first indicated TCI state in the DCI for the first PDSCH transmission opportunity when receiving the AP CSI-RS.

[0195]

[0036] Embodiment 36: The method of any one of embodiments 21 to 35, further comprising: assuming (1406) that when a single triggered AP CSI-RS is in the same symbol as the second PDSCH transmission opportunity, the wireless device applies the QCL assumption given by the second indicated TCI state in the DCI for the second PDSCH transmission opportunity when receiving the AP CSI-RS.

[0196]

[0046] Embodiment 37: The method according to any one of embodiments 21 to 36, wherein the scheduling offset from the last symbol of the PDCCH to the first symbol of the first PDSCH transmission opportunity and the scheduling offset from the last symbol of the PDCCH to the first symbol of the second PDSCH transmission opportunity are both less than a threshold timeDurationForQCL.

[0197]

[0036] Embodiment 38: The method of any one of embodiments 21 to 37, further comprising: assuming (1406) that when a single triggered AP CSI-RS is in the same symbol as the first PDSCH transmission opportunity, the wireless device applies the QCL assumption given by the first default TCI state in the DCI for the first PDSCH transmission opportunity when receiving the AP CSI-RS.

[0198]

[0036] Embodiment 39: The method of any one of embodiments 21 to 38, further comprising: assuming (1406) that when a single triggered AP CSI-RS is in the same symbol as the second PDSCH transmission opportunity, the wireless device applies the QCL assumption given by the second indicated TCI state in the DCI for the second PDSCH transmission opportunity when receiving the AP CSI-RS.

[0199]

[0081] Embodiment 40: The method of any one of embodiments 21 to 39, further comprising obtaining user data and forwarding the user data to a host computer or a wireless device.

[0200] Group C Embodiments

[0201] Embodiment 41: A wireless device for determining a transmission configuration indication (TCI) state for receiving one or more aperiodic (AP) channel state information reference signals (CSI-RS), the wireless device comprising: a processing circuit configured to perform any of the steps described in any one of the embodiments of group A; and a power supply circuit configured to supply power to the wireless device.

[0202] Embodiment 42: A base station for indicating a transmission configuration indication (TCI) state for receiving one or more aperiodic (AP) channel state information reference signals (CSI-RS), the base station comprising: a processing circuit configured to perform any of the steps described in any one of the embodiments of Group B; and a power supply circuit configured to supply power to the base station.

[0203] Embodiment 43: A user equipment (UE) for determining a transmission configuration indication (TCI) state for receiving one or more aperiodic (AP) channel state information reference signals (CSI-RS), the UE comprising: an antenna configured to send and receive wireless signals; a radio front-end circuit connected to the antenna and a processing circuit and configured to condition signals communicated between the antenna and the processing circuit, the processing circuit configured to perform any of the steps described in any one of the embodiments of Group A; an input interface connected to the processing circuit and configured to enable input of information to the UE to be processed by the processing circuit; an output interface connected to the processing circuit and configured to output information from the UE processed by the processing circuit; and a battery connected to the processing circuit and configured to provide power to the UE.

[0204] Embodiment 44: A communications system including a host computer, the host computer having a processing circuit configured to provide user data and a communications interface configured to forward the user data to a cellular network for transmission to a user equipment (UE), the cellular network having a base station having a wireless interface and a processing circuit, the processing circuitry of the base station configured to perform any of the steps described in any one of the embodiments of Group B.

[0205] Embodiment 45: The communication system of embodiment 44, further comprising a base station.

[0206] Embodiment 46: The communication system of embodiment 44 or 45, further comprising a UE, the UE being configured to communicate with the base station.

[0207] Embodiment 47: A communication system as described in any one of embodiments 44 to 46, wherein the processing circuitry of the host computer is configured to execute a host application thereby to provide user data, and the UE comprises processing circuitry configured to execute a client application associated with the host application.

[0208] Embodiment 48: A method implemented in a communication system including a host computer, a base station, and a user equipment (UE), the method including: providing user data at the host computer; and initiating a transmission at the host computer conveying the user data to the UE via a cellular network including the base station, the base station performing any of the steps described in any one of the embodiments of Group B.

[0209]

[0081] Embodiment 49: The method of embodiment 48, further comprising transmitting user data at the base station.

[0210] Embodiment 50: The method of embodiment 48 or 49, wherein the user data is provided by executing a host application at the host computer, and the method further includes executing, at the UE, a client application associated with the host application.

[0211] Embodiment 51: A user equipment (UE) configured to communicate with a base station, the UE comprising a radio interface and processing circuitry configured to implement a method according to any one of embodiments 48 to 50.

[0212] Embodiment 52: A communications system including a host computer, the host computer having a processing circuit configured to provide user data and a communications interface configured to forward the user data to a cellular network for transmission to a user equipment (UE), the UE having a wireless interface and a processing circuit, the components of the UE being configured to perform any of the steps described in any one of the embodiments of Group A.

[0213]

[0081] Embodiment 53: The communication system of embodiment 52, wherein the cellular network further includes a base station configured to communicate with the UE.

[0214] Embodiment 54: A communications system as described in embodiment 52 or 53, wherein processing circuitry of the host computer is configured to execute a host application thereby providing user data, and processing circuitry of the UE is configured to execute a client application associated with the host application.

[0215] Embodiment 55: A method implemented in a communication system including a host computer, a base station, and a user equipment (UE), the method including: providing user data at the host computer; and initiating a transmission at the host computer conveying the user data to the UE via a cellular network including the base station, the UE performing any of the steps described in any one of the embodiments of Group A.

[0216]

[0081] Embodiment 56: The method of embodiment 55, further comprising: receiving, at the UE, user data from the base station.

[0217] Embodiment 57: A communications system including a host computer, the host computer having a communications interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station, the UE having a wireless interface and processing circuitry, the UE's processing circuitry configured to perform any of the steps described in any one of the embodiments of Group A.

[0218] Embodiment 58: The communication system of embodiment 57, further comprising a UE.

[0219] Embodiment 59: The communication system of embodiment 57 or 58, further comprising a base station, the base station having a radio interface configured to communicate with a UE and a communication interface configured to forward user data carried by a transmission from the UE to the base station to a host computer.

[0220] Embodiment 60: A communications system as described in any one of embodiments 57 to 59, wherein processing circuitry of the host computer is configured to execute a host application and processing circuitry of the UE is configured to execute a client application associated with the host application, thereby providing user data.

[0221] Embodiment 61: A communication system as described in any one of embodiments 57 to 60, wherein processing circuitry of the host computer is configured to execute a host application thereby providing requested data, and processing circuitry of the UE is configured to execute a client application associated with the host application thereby providing user data in response to the requested data.

[0222] Embodiment 62: A method implemented in a communication system including a host computer, a base station, and a user equipment (UE), the method including receiving, at the host computer, user data transmitted from the UE to the base station, and the UE performing any of the steps described in any one of the embodiments of Group A.

[0223]

[0081] Embodiment 63: The method of embodiment 62, further comprising, in the UE, providing user data to the base station.

[0224] Embodiment 64: The method of embodiment 62 or 63, further comprising: executing, in the UE, a client application thereby providing user data to be transmitted; and executing, in the host computer, a host application associated with the client application.

[0225] Embodiment 65: A method according to any one of embodiments 62 to 64, further comprising: executing a client application in the UE; and receiving input data in the UE for the client application, the input data being provided in a host computer by executing a host application associated with the client application, and the user data to be transmitted being provided by the client application in response to the input data.

[0226] Embodiment 66: A communications system including a host computer, the host computer having a communications interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station, the base station having a wireless interface and processing circuitry, the processing circuitry of the base station configured to perform any of the steps described in any one of the embodiments of Group B.

[0227] Embodiment 67: The communication system of embodiment 66, further comprising a base station.

[0228] Embodiment 68: The communication system of embodiment 66 or 67, further comprising a UE, the UE being configured to communicate with the base station.

[0229] Embodiment 69: A communication system as described in any one of embodiments 66 to 68, wherein the processing circuitry of the host computer is configured to execute a host application, and the UE is configured to execute a client application associated with the host application, thereby providing user data to be received by the host computer.

[0230] Embodiment 70: A method implemented in a communications system including a host computer, a base station, and a user equipment (UE), the method including receiving, at the host computer, from the base station, user data originating from a transmission received by the base station from the UE, the UE performing any of the steps described in any one of the embodiments of Group A.

[0231]

[0081] Embodiment 71: The method of embodiment 70, further comprising: receiving, at the base station, user data from the UE.

[0232]

[0081] Embodiment 72: The method of embodiment 70 or 71, further comprising initiating, at the base station, transmission of the received user data to the host computer.

[0233] At least some of the following abbreviations may be used in this disclosure. In case of inconsistencies between abbreviations, how the abbreviation is used above should be preferred. If listed multiple times below, the first listing should be preferred over subsequent listing(s). · 3GPP 3rd Generation Partnership Project 5G (fifth generation) 5GC 5th generation core 5GS 5th generation system AF Application Features AMF access and mobility features AN Access Network AP Access point ASIC Application Specific Integrated Circuit AUSF authentication server function CPU Central Processing Unit DN Data Network DSP Digital Signal Processor eNB Enhanced or evolved Node B EPS Evolved Packet System E-UTRA Enhanced Universal Terrestrial Radio Access FPGA Field Programmable Gate Array · gNB New wireless base station gNB-DU New Radio Base Station Distributed Unit HSS Home Subscriber Server IoT Internet of Things IP Internet Protocol LTE Long Term Evolution MME Mobility Management Entity MTC Machine Type Communication NEF network publishing function NF network function · NR new radio NRF Network Function Repository Function NSSF network slice selection function OTT (Over the Top) PC Personal Computer PCF policy control function P-GW Packet Data Network Gateway QoS Quality of Service RAM Random Access Memory RAN Radio Access Network ROM Read-Only Memory RRH Remote Radio Head RTT Round Trip Time SCEF Service Capability Exposure Function SMF session management function UDM Integrated Data Management UE User Equipment UPF user plane function

[0234] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure, and all such improvements and modifications are considered within the scope of the concepts disclosed herein.

Claims

1. 1. A method performed by a wireless device for determining a transmission configuration indication (TCI) state for receiving one or more aperiodic (AP) channel state information reference signals (CSI-RS), the method comprising: receiving 1302, in a physical downlink control channel (PDCCH), downlink control information (DCI), triggering of one or more AP CSI-RS in one or more symbols, at a first time offset between a last symbol of the PDCCH and a first symbol of the one or more symbols containing the AP CSI-RS, where the first time offset is less than a first threshold; determining a quasi-co-location (QCL) assumption for receiving the one or more AP CSI-RS based on a plurality of TCI states associated with one or more downlink transmissions in the same one or more symbols as the one or more AP CSI-RS, the plurality of TCI states being indicated in a DCI scheduling the one or more downlink transmissions, and if the first time offset is less than the first threshold, the determined QCL assumption is a QCL assumption given by a TCI state of one or more downlink PDSCH transmissions in the symbols for receiving the one or more AP CSI-RS in the same one or more symbols; receiving 1300 the one or more AP CSI-RS in the one or more symbols using the determined QCL hypotheses; Including, the first threshold value comprises a beamSwitchTiming value reported by the wireless device; method.

2. the one or more downlink transmissions include one or more Physical Downlink Shared Channel (PDSCH) transmissions; the one or more PDSCH transmissions are scheduled by a DCI carried in a PDCCH; 2. The method of claim 1, wherein a second time offset between a first symbol of the PDCCH carrying the DCI scheduling the one or more PDSCH transmissions and a first symbol of the PDSCH is greater than or equal to a second threshold.

3. each of the one or more downlink transmissions is associated with one of the plurality of TCI states; and / or the one or more downlink transmissions are one or more PDSCH repetitions in the time domain or in the frequency domain; and / or The one or more downlink transmissions comply with one of the schemes “TDMSchemeA”, “FDMSchemeB” or “FDMSchemeA”, and / or 3. The method of claim 1, wherein the one or more downlink transmissions are one or more sets of layers of a PDSCH, each set of layers being associated with one of the plurality of TCI states, and the wireless device is configured to receive PDSCH according to a single PDCCH-based NC-JT scheme.

4. the plurality of TCI conditions includes a first TCI condition and a second TCI condition; and / or The method of claim 1 , wherein the one or more symbols are one or more Orthogonal Frequency Division Multiplexing (OFDM) symbols.

5. The method of claim 2 , wherein the second threshold is a timeDurationForQCL value reported by the wireless device.

6. the determined QCL assumption is a QCL assumption for receiving the one or more AP CSI-RS in the same one or more symbols given by a first indicated TCI state in a DCI for the PDSCH in a symbol when the one or more downlink transmissions are one or more sets of layers of a physical downlink shared channel (PDSCH), each set of layers being associated with one of the plurality of TCI states; the determined QCL hypothesis is a QCL hypothesis for receiving the one or more AP CSI-RS in the same one or more symbols given by a TCI state of the one or more downlink PDSCH transmissions in a symbol when the one or more downlink PDSCH transmissions are one or more PDSCH repetitions in the time domain, each of the one or more PDSCH transmissions being associated with one of the multiple TCI states; 6. The method of claim 1, wherein the determined QCL assumption is a QCL assumption for receiving the one or more AP CSI-RS given by a first TCI state of the plurality of TCI states.

7. The method of claim 2 , wherein the second time offset is less than a timeDurationForQCL value.

8. the plurality of TCI states include a first default TCI state and a second default TCI state, the first default TCI state and the second default TCI state being associated with a code point of a TCI field in a DCI having a lowest code point value; a single triggered AP CSI-RS is in the same symbol as a downlink PDSCH transmission, and the determined QCL hypothesis is a QCL hypothesis for receiving the AP CSI-RS given by a first default TCI state of the PDSCH; 8. The method according to any one of claims 1 to 7.

9. two triggered AP CSI-RS are in the same symbol as a PDSCH associated with the first TCI state and the second TCI state; the determined QCL assumptions are QCL assumptions for receiving a first AP CSI-RS and a second AP CSI-RS given by the first default TCI state and the second default TCI state of the PDSCH, respectively; The method according to claim 8, which recites claim 4.

10. 1. A method performed by a base station for indicating a transmission configuration indication (TCI) state for receiving one or more aperiodic (AP) channel state information reference signals (CSI-RS), the method comprising: signaling in a physical control channel (PDCCH) in downlink control information (DCI) to a wireless device regarding one or more AP CSI-RS to be transmitted to the wireless device in one or more symbols, where one or more downlink transmissions associated with two TCI states are also to be transmitted in the same symbols, and a first time offset between the PDCCH and the one or more AP CSI-RS is less than or equal to a first threshold; determining a quasi-co-location (QCL) assumption for transmitting the one or more AP CSI-RS based on a TCI state of the one or more downlink transmissions, where the two TCI states are indicated in a DCI scheduling the one or more downlink transmissions, and if the first time offset is less than the first threshold, the determined QCL assumption is a QCL assumption given by a TCI state of one or more downlink PDSCH transmissions in a symbol for receiving the one or more AP CSI-RS in the same one or more symbols; transmitting 1400 the one or more AP CSI-RSs in the one or more symbols according to the QCL assumption to the wireless device; Including, the first threshold value comprises a beamSwitchTiming value reported by the wireless device; method.

11. the one or more downlink transmissions include a Physical Downlink Shared Channel (PDSCH) transmission(s); the PDSCH transmission is scheduled by a DCI format carried in a PDCCH; a second time offset between the PDCCH and the PDSCH is greater than or equal to a second threshold; The method of claim 10 , wherein the first threshold and the second threshold are reported by the wireless device.

12. each of the one or more downlink transmissions is associated with one of the two TCI states; the one or more downlink transmissions are one or more PDSCH repetitions in the time domain; and / or the one or more downlink transmissions are one or more sets of layers of a PDSCH, each set of layers being associated with one of the two TCI states, and the wireless device is configured to receive a PDSCH according to a single PDCCH-based NC-JT scheme; and / or the two TCI states are indicated in the DCI that schedules the one or more PDSCH transmissions; and / or the two TCI conditions include a first TCI condition and a second TCI condition; and / or 12. The method of claim 10 or 11, wherein the one or more symbols are one or more Orthogonal Frequency Division Multiplexing (OFDM) symbols.

13. The method of claim 11 , wherein the second threshold comprises a timeDurationForQCL value reported by the wireless device.

14. the QCL assumption is a QCL assumption for transmitting the one or more AP CSI-RS given by a first TCI state of the PDSCH when the one or more downlink transmissions are one or more sets of layers of a PDSCH, each set of layers being associated with one of the two TCI states; the QCL assumption is a QCL assumption for transmitting the one or more AP CSI-RS in the same symbol given by a TCI state of the one or more downlink PDSCH transmissions in a symbol when the one or more downlink PDSCH transmissions are one or more PDSCH repetitions in the time domain, each of the one or more PDSCH transmissions being associated with one of the two TCI states; 14. The method of claim 10, wherein the QCL assumption is a QCL assumption for transmitting the one or more AP CSI-RS given by a first TCI state of the two TCI states.

15. The method of claim 11 , wherein the second time offset is less than a timeDurationForQCL value.

16. the two TCI states include a first default TCI state and a second default TCI state, the first default TCI state and the second default TCI state being associated with a code point of a TCI field in the DCI having a lowest code point value; 16. The method according to any one of claims 10 to 15.

17. A single triggered AP CSI-RS is in the same symbol as a PDSCH, and the QCL assumption is the QCL assumption when transmitting the AP CSI-RS given by a first default TCI state for the PDSCH; and / or two triggered AP CSI-RS are in the same symbol as a PDSCH, and the QCL assumptions are QCL assumptions when transmitting a first AP CSI-RS and a second AP CSI-RS, respectively, given by the first default TCI state and the second default TCI state for the PDSCH; 17. The method of claim 16.

18. 28. A wireless device for activating a transmission configuration indicator (TCI) state, comprising: One or more transmitters (2808); One or more receivers (2810); a processing circuit (2802) associated with said one or more transmitters (2808) and said one or more receivers (2810); 10. A wireless device (2800) comprising: a processing circuit (2802) configured to cause the wireless device (2800) to perform a method according to any one of claims 1 to 9.

19. A base station (2500) for activating a transmission configuration indicator (TCI) state, comprising: One or more transmitters (2512); One or more receivers (2514); a processing circuit (2504) associated with said one or more transmitters (2512) and said one or more receivers (2514); 20. A base station (2500) comprising: a first receiving unit (2504) for receiving a first signal from a first receiving node (2506) and a second receiving unit (2508) for receiving a second ...).

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